Role of a ball in a fountain pen's converter

I don't have that particular pen, so I can't view the ball you're referring to.  However, I suspect what it is.
Fountain pens work by capillary action; a minute amount of ink is allowed to flow to the nib.  If you tried to refill the pen at that rate, it would take forever (about the time it would take you to use up the ink in the pen by writing).  The converter contains some form of valve that opens when you suck ink into it, and seals when you're not refilling.
A ball is a common mechanism for a valve.  Something springy holds it against an opening so the opening is normally sealed.  Negative pressure inside during refilling pulls the ball away so ink can enter quickly.  However, other kinds of valve mechanisms can be used, or if there is a ball, it may just not be in a visible location in some converters.
If the ball in your converter is free to move around in the tank, then it likely serves a different function.  If you fill the pen with pigment-based ink, there might be a tendency for the ink components to settle or separate if the pen is stored full.  The ball could serve the same function as the mixing ball in a spray can.  Just changes in the pen's orientation when writing and putting the pen down or in a pocket would move the ball through the ink and keep the ink uniformly mixed.


Re-bending a bent plastic figure to stand up straight

Try to repeat the procedure, but bend it in the opposite direction, until it cools down (or even more, to be sure). While it will tend to come back, it might stop (close) to the vertical position.

You may need to repeat for a few times. Do not force it too much, as it can break.


How can one blow/work with borosilicate glass to a container of precise dimensions?

Borosilicate also goes by the brand name Pyrex. If you perform a search for "borosilicate glass cylinder" you will find some sources of various sizes of tubing.

If you have access to a sufficient powerful heat source, you can heat the tubing and force it to close.

A quick bit of research shows the working temperature to be 1245°C, attainable by MAPP gas torches at the consumer level. If you know someone who does gas welding, oxy-acetylene torches will reach the necessary temperatures at a lower cost overall.


How can I loosen the joints on my action figures without breaking them?

WD-40 and similar oils contain solvents, which would most likely strip the paint off your model.

A "dry" bike-chain oil will do well to reduce friction.

However the teflon particles are dispersed in a solvent, so it's hard to say how it might effect the paint.

If you go this route, use a toothpick to apply to the inside of the knuckles, for precision without dripping all over the rest of your model.

A light sewing-machine oil should also be suitable.
They tend to penetrate well without any added solvents.

...

I would think a toothpick would be safer than an x-acto knife because the toothpick would "give" if you apply too much pressure, smooshing down before your plastic does.

If it's not strong enough, you can go the X-acto route, or craft pick; a compass point might do.

My main thought was that the toothpick would hold a drop of oil well,
like a candlewick does, plus it's fine enough to get inside.

You could cut the cotton off a Q-tip at an angle and wedge some oil in there that way if you like.

Again, being softer than the plastic, it should bend before damage is done to your model.

Don't expect it to crack instantly. Just keep wiggling the oil in there for a while 'till it gives.

You're right about the hot water trick. If kept low it should be OK. Like 100°F. You know, baby-water warm.  Hot, not scalding.  If you need it in there for a long period of time, maybe set a pot of water on one of those coffee/candle-warmer pads.

Put model in a freezer-bag and do it sous-vide style, so it doesn't get completely soaked.  Put something heavy in the bottom of the bag so it doesn't float.


If you are more interested in subtractive sculpting (removing material rather than adding it like clay), I spent my earliest sculpting days carving bars of Ivory soap. There may be softer brands, but you know Ivory soap is 99-44/100% pure <grin>.

How to Make a Soap Carving

A sharp knife is not necessary. Plastic knives, spoons, or Popsicle sticks could also work. But I suggest investing in a modest set of clay sculpting tools made of wood (less than US$5.00). They are tough enough to stand up to the soap without having a tendency to snap like plastic knives or Popsicle sticks.

Product Search:  Wood Sculpting Tools


Recipe to Make Pastel Ground/Primer with Marble Dust

I would look into a mixture of gum arabic dissolved in buttermilk, chalk whiting, a bit of almond oil and your marble dust, add your pigment and a drop of clove oil to keep the organic from going off.

500g gum arabic
1000ml buttermilk
250g - 500g chalk
250g - 500g marble dust
2-5g almond oil
Pigment
Clove oil

Bring buttermilk in a pot to about 80 degrees Celsius - don’t boil. Whisk in gum arabic until it is dissolved. Remove from heat. Add oils. Add chalk and marble dust until you get the thick paste you are comfortable with. Knead the paste like dough and until pigment is well mixed. Roll into sticks, let dry.

Don’t trust this recipe blindly, because chalk, pigment and gum arabic have different properties depending on purity and chemical composition. You’ll have to use your intuition and experience. You could use water instead of buttermilk. You could sump the chalk and marble in distilled water for 24 hours.


What is the best way to create a stencil for a large spray paint image?

The best first step is to convert your image into a vector format from the current raster image. Vector format images are composed of "descriptions" that could be considered as a road map of the image. As an example, a square can be defined as four points and four lines. The vector image can be easily processed by laser cutter, vinyl cutter and CNC router if you have access to these machines or are in an area with a makerspace.

If you need only one use of the image, you could have it cut in vinyl, apply it to the surface, cast your media and remove the vinyl. I suspect that it would be less expensive to have a stencil cut rather than vinyl.

A quick search for "stencil cutting services" shows me there are many resources in that respect.

If you will be creating this stencil for multi-color results, you will have to have a color separation of the vector image, with registration marks as part of the output. That is to say, you would have a set of openings on one stencil for the black, another stencil for the red.

One critical consideration is the detail and resolution of your image. The image you've posted shows dithering. This is the area where small dots appear in one color with another color as the background. This can be challenging for the cutter, if you do not perform the raster to vector conversion yourself. If you do the conversion, you will also find it challenging.

Consider how your image will appear if the dithering is removed or converted to solid colors. Will that be acceptable? Also consider to search using the terms "david bowie vector image" for a better choice of your stencil.

As an example, I found this as a result of the search:

Note that the edges are crisp and solid. Two colors means a single stencil, more easily accomplished for a reasonable price.

Another caution. This image and almost any you find will have floaters in the stencil. These are sections that have no attachment to the edge of the stencil. Stencil fonts always have the floaters secured to the edges. Art work cannot have the luxury and attain the desired result. As such, it may be necessary to resort to one-shot vinyl, as the stencil remains attached to transfer tape until applied to the surface, keeping the floaters in place until peeled from the surface. Bowie's right eye is an example if you consider that the stencil material is black and the medium is white paint. Curiously, in this example, it would appear that only his eye and nostril are floaters and the rest of the stencil is well secured by the neck area.

Some stencils can be secured by very thin strips of edited lines but have to be treated carefully in handling to avoid breaking those attachment points. In the example image, one could create a connection from the left edge of his eye to the outside and another from the right edge of the eyebrow to the right side, a thin uni-brow.

In your post, you suggest a 3' x 2' poster, which would require tiling of the stencils, I expect. You would be able to find a service that can cut the entire full size, but it might not be inexpensive.

I think the most difficult part of your project would be to find a satisfactory vector image and the remainder is simply money or labor. If you have a good vector image and good stencil material, you could print the image in tiles, cut the vector lines with a hobby knife and create it on your own.

If you create your own, you can also consider to apply spray adhesive to the tiles, attach the uncut stencil to the MDF and begin the cutting process. This also removes the problem of floating sections, as the adhesive will secure them. Some spray adhesive will release relatively easily, as will rubber cement when properly applied. MDF doesn't hold well with such adhesives, but will hold well enough for stencil cutting purposes.


Nep

  Generally, a nep is defined as an entanglement of fibers, that can be caused by environmental factors during growth, processing or are inherent to particular varieties.

abtexintl.net

hm.com

indiamart.com

taylorstitch.com

asos.com

Fleck Nep

superdenim.com

realmccoyslondon.com

Flecked Corduroy


Is there a way to cleanly cut styrofoam?

Is there a trick or special tool to make clean cuts without making a mess of little styrofoam bits everywhere?

Yes, it's called "hot-wire (foam) cutter" which can be bought starting at prices of about $20, or you can also make one yourself.

The hot wire melts the styrofoam, releasing toxic fumes (styrene), so it's best to use it in a well-aerated room or outside. (See e.g. this link for more safety advice.)
It will work on styrofoam, but probably not very well on soft foams.


You could try fray check. These glues tend to be thinner, which would give you a less noticeable and stiff edge. They are usually clear, but may yellow over time.

If that isn't strong enough, you could try fabric glue, which as the name suggests, is specifically made for bonding fabrics.

You can also finish the back of your piece without glue! After mounting on a board or in a hoop, fold the raw edges under and stitch across from one side to another, keeping the fabric taut and in place. You can then cover up the back by sewing on another piece of fabric. This is often done with felt which does not fray, but you could use any fabric as long as you tuck the raw edges under.


I am no expert, but a simple Google search gave me a very clear answer. The cone of vision is the spatial volume seen by a (dimensionless) observer inside an angle of 60o.

To "calculate" the envelope (margin) of the cone, you "draw" all the lines originating at the observer and being at an angle of 30o away from the line of sight.

Everything outside this cone is considered "out-of-sight".

Notes:

For humans (and most living creatures possessing vision), there are two distinct cones of vision, one for each eye. The relative position of the two  cones varies greatly, depending on the relative position of the eyes (e.g., both eyes to the front, like humans, or eyes to the sides, lie fish). Eye movement leads to movement of the cone of vision.
For how to successfully use the concept of "cone of vision" in drawing, architecture or anything else, you need to get further knowledge on all these subjects.


Do high-temp vacuum-sealed reusable bags exist?

There are silicone sealable and reusable food storage bags like these that are good for over 400 degrees: Silicone Food Storage Bags Reusable (looks like this particular product isn't currently available at Amazon, but you can find similar items or they may come back into stock; at least it's clear that such products exist).
They are sealed with a channel that slides over the opening.  What comes with it looks like plastic, so you would need to make a similar channel or clip out of metal or some other material that would withstand the high temperature.  You would also need to figure out how to suck out the air and complete the sealing of it.  It might require embedding a tube at one end of the opening, sealing the bag, evacuating it, then sealing the tube.
One other product I can think of that will take the temperature is Reynolds Oven Bags, which works in a 350F oven and comes in various sizes.  Those are designed to be tied with a provided nylon string.  It isn't clear how many uses you would get from a bag, but they're a lot cheaper than the silicone bags.  Again, you would need to find a way to suck out the air and seal it.  You could do something like wrap the opening around a tube, suck out the air, than tightly twist and tie the bag below the tube, perhaps folding the twisted area.
Creating an air-tight evacuation port in a sealable bag can be done, but is often a challenge.  The OP reports a clever idea to solve this.  Sous vide is a cooking method that involves sealing the food in a vacuum bag and cooking it in a water bath at a controlled temperature.  Silicone bags are available for this purpose, and come with an evacuation port built-in.
The OP found these Sous Vide Silicone Bags and reports that they worked.


How to dry out epoxy resin faster than usual?

To cure them more quickly you can either:

use heat lamps or an electric heater over your resin pieces
raise the temperature of the room they are in to say, 75 - 85°F / 24 - 30°C.

If you do either of these, you must maintain the heat constantly until fully cured.

Don't be tempted to add more hardener as it can stop the resin curing and remain sticky indefinitely.

There are additives that promote curing (called accelerator) however they are typically yellow in colour so will add a slight yellow hue to the resin.  Also, the faster the resin cures, the greater the chance of it yellowing as a combination of the heat by-product of resin curing and heat applied to cure the resin faster.

There are reduced accelerator resins around which are slower curing but cure clearer.

To prevent dust from settling on the resin while curing, you can cover them with a cloche or bowl.

For more info on what I have said, you can read what ArtResin say at https://www.artresin.com/blogs/artresin/44707073-how-to-make-resin-cure-faster


A few thoughts:

If the hole is being destroyed, you may be wearing the belt tighter than the leather will support.  If the belt is otherwise in good shape, you may be able to make a cosmetic repair to the hole, then use the belt at the next looser hole.
Cosmetic repair: If the leather is torn, try the grommet solution, below, after this repair.  If the hole is just stretched, try pressing it flat, using a tool to push the leather around the hole back into shape.  If needed, use shoe dye or a Magic Marker of the same color to restore color to areas around the hole.  Then apply super glue (thin liquid version) on the backside to saturate the leather around the hole.  Cover both sides of the repair with baking paper (it's silicone treated so the glue won't stick to it), put the repair under a weight, like a heavy book, and leave it overnight.
Functional repair: If you want to continue using the belt at the same hole, there are limited options for a repair that will hold up comparable to the original leather.  That type of buckle typically has a short hook that won't reach through the thickness of an added patch layer on the back.  You need a way to reinforce the hole.

The most practical way to do that is with a grommet.  If the buckle hook is right at the edge of the buckle and the grommet would be exposed and noticeable, you have a couple of choices.  One is to grind away the exposed edge of the grommet head before installing it (you then need to be careful about its orientation when you install it).  Another is to just add grommets to all exposed holes for a uniform appearance (they can be colored to match the belt, but they won't have the dress appearance of plain leather).

Start with the cosmetic repair described above.  For the grommet going into the damaged hole, augment it with two things.  One is a thin metal washer on the back side.  They may come with the grommets.  If not, cut one from a beverage can (just be sure there are no sharp edges or burs that can damage the trousers).

The grommet may have a "cupped" head to grab the leather and spread the stress over more than just the hole.  If not, glue the grommet and washer to the leather when installing it (even with a cupped head, it wouldn't hurt to glue the washer to reinforce the leather).  Use a neoprene-based glue like E6000, and wipe off the excess.  Let that dry for a few days (or at least until you can no longer smell the solvent) before using the belt.
That type of buckle typically attaches to the belt via a clamp on the backside.  The clamp pries open and snaps shut.  You can just replace the leather portion with another of the same width.  You can buy the strap without a buckle, or buy another belt long enough that you can cut off the buckle and insert the leather strap in this buckle.  One strategy is just to buy a cheap belt the right width, cut off the buckle and use the strap for as long as it lasts, then replace it again when it wears out.


It's unusual for the problem to be the pencil unless it's been damaged, like by dropping it on the tip.  The most common issues are remnants of old leads being pushed out by the new lead, a jam, or defective leads.
Start by releasing and dumping all of the leads and lightly tapping the back end of the pencil on a hard surface to encourage any lead fragments to fall out.
I'm not sure about rOtring, but many 0.5 mm pencils come with a cleaning wire (often stuck into the backside of the eraser).  If it didn't come with one, find a thin straight pin or piece of stiff wire thin enough to fit into the tip.  While depressing the feed actuator all the way to open the feeding collet, slide the cleaning wire through the tip to dislodge any lead remnants that might be stuck, inserting it far enough to go all the way through the tip and feed mechanism.
If you don't have anything to use as a cleaning wire, disassemble the pencil all the way to the feed components.  Inspect everything to ensure there aren't lead bits stuck in anything, or lead dust packed somewhere.  Then reassemble it.
Take a good lead and carefully insert it through the tip while fully depressing the feed button to open the feed mechanism.  Push the lead all the way in so only a normal amount of lead is exposed, then release the feed button.  Work the feed button a few times to verify that the lead feeds without breaking.
If it works, you're done and can load in some extra leads.  Don't overload the pencil with too many extra leads, though.  The spare leads need room to move in order to load when you finish the previous one.
If the lead breaks when you try feeding it, try again loading a harder lead.  If that feeds without breaking, the problem is the leads.  It could be a bad batch.  If the hard lead also breaks, that would point to the pencil being damaged.


Begin cleaning by gently brushing the surface of the object with a soft brush to remove loose dirt and dust. If soiling is heavy, brush debris into a HEPA vacuum with cheesecloth over the nozzle to catch any bits of paper that may come loose accidentally. Just don't apply the vacuum hose directly onto the object.


Aggregate size and mix ratio for concrete sculptures

There are two scenarios to consider:

Molding and Sculpting

For molding, most use a 1/4" to 3/8" aggregate.  Using larger aggregate may force aggregate to migrate to the surface.

The ratio depends on how big the statue will be.

Typical mix:
   1 part  Portland Cement (white cement ratio is the same)
   2 parts Sand (nothing fancy - its the connector for the cement to grab hold of)
   1 part  Aggregate (Gravel) - this can be as big or small depending on preference.
           most use the Pea Gravel sized rocks for statuary.

It may be necessary to increase the amount of aggregate to 2 parts in bigger pieces like the life-sized ones as described.

Additional things to add and think about:
  1) Add a Acrylic Bonding Liquid to help the mix stay together better.
  2) Add Alkaline Resistant (AR) Fibers and Mesh to the pieces to help with strength.
  3) Add metal wire - Rebar or stiff wire - to help with strength and flexibility.

Pointers for molding:

Concrete in molds can trap air bubbles and distort the surface of the piece.  To combat this, vibrate the mold to release air bubbles - tapping the sides of the mold or vibrating the entire mold with a mechanical device.

Experiment with making the mixture thicker or thinner to allow the bubbles to release without needing to vibrate them away.

If there are voids created by bubbles or mold issues, create a slurry of cement and water to fill the gaps and smooth them over

To finish the piece use a stone rasp, file, grinder, or sand paper while the surface is still damp.  Be careful as the surface is not cured and may mar or damage easily.

For actual sculpting:
   1 part  Portland Cement
   2 parts Sand

This mixture much less stable and can be shaped and worked.  This is really just a mortar and not concrete.

When making a large structure, something bigger is needed to support the cement.  Different ideas for use are:
Styrofoam (Extrude Polystyrene - EPS),
Backer board,
wood,
metal,
wire,
plastic,
paper,
cans,
glass bottles,
and anything to take up space and provide support.

Structures can be similar to the type used with topiary designs, but these won't be hollow.

After making the piece, it's important to let it cure and to seal it.  Any concrete exposed to the outdoor elements will deteriorate and lose it's details if left unprotected.  Clear varnish or sealers are the best choices, but be sure to use Outdoor products.

Curing times vary depending on the thickness, humidity, and temperature.  The longer, the better.  Keep the piece from undergoing extreme changes (temperature and humidity) to minimize the cracking and possible powdering/flaking. A slow cure with a stable environment is best.

The longer the cure, the stronger the piece will be.  For smaller pieces, wrapping in plastic is the most common way.  Misting or wetting the surface will help the humidity to remain stable and promote the curing.  The curing can take from 3-4 days to two weeks.  The process is done from the outside inward.  Many cracked concrete slabs that were poured years ago and are still damp in the center.

Some of the better instructional videos can outline specific methods and procedures.

There are good YouTube videos about concrete casting and sculpting from these channels:

Rubbermoldman (aka P. David Jensen)
Mrconcreteartisan
Microcast Molds
T.TB- Construction - Specific to sculpting with mortar on top of other pieces.

Happy Casting !


Looking for a springy thin wire to make earrings with

The look of it strongly reminds me of christmas tree balls. They even work according to the same principle.

Maybe you have some old christmas tree balls you don't like anymore or one that's broken. Pull the cap out and remove the wire from the rest of the cap.


I think what you are looking for is called a masking fluid. It is sometimes also called liquid frisket.

Masking fluid can be treated like paint which wherever it is applied will protect what is underneath. A feature of most masking fluids is that they are removable once dry.

Some masking fluids are strongly hydrophobic (water repellent), and water will bead on its surface. This can make it tricky to tell when the whole canvas is dry. Trying to remove the masking fluid but having some undried paint pooling on the surface can cause heartbreaking smears.

Some masking liquids change colour after they dry. This makes it easier to see where you have applied it, and easier to tell if you have removed it all after the work is complete.

Masking fluid is great for creating negative visual effects, like you describe.


What should I look for in a paper for a complex origami model?

When rejecting DIY solutions, you are limiting your choice a lot. Methylcellulose (MC)-glued double and triple tissue and well as self-made tissue foil are very popular and relatively inexpensive materials for folding exactly the kind of models you describe.

The situation is not hopeless, however. There are ready-made papers which may suit your needs, but you will usually have to pay dearly for the benefit of not having to prepare paper yourself.

For practice, Kraft paper is often very good. It is widely available, strong, and you can get it in a range of thicknesses, including thin (e.g. 40 gsm). It does not look too good, but its folding properties are quite nice and it is inexpensive. You can usually get some variant in a local art supply store and save on shipping fees. This kind of paper often comes in rolls in which case you can get large formats, even above 1 m, easily (you have to cut the square yourself in such case, though).
Nicolas Terry Tissue Foil is a ready-to-use replacement for self-made tissue foil and seems to be thinner than what you can make yourself.
Various mulberry papers can be good for this sort of models. They are available online and sometimes in art supply stores (depending on where you live).
A broad range of Washi papers are suitable for complex models. Be careful, however as Washi can mean a lot of different things, from very thin to rather thick. Be sure to check the weight / thickness of the paper.
A number of hand made papers may be suitable but since they are all unique, and often do not even have an official weight rating, it may be hard to find the right one without touching it or having a qualified seller who knows origami choose one for you.
And of course at the high end there's some Origamido available online. That's what Robert Lang often uses for his best models, though it comes with a price tag of €13 per sheet.

These were some specific paper types which may (or may not) fit your model. Note that each particular model may have different requirements on thickness and stiffness of the paper. For example, Shuki Kato's elephant can certainly be considered a complex model (196 steps) but it can be, and very often is, folded from Elephant Hide paper (110 gsm) which is an absolute no go for most insect models.

So, think about a particular model. What you can do is search flickr or other places where lots of origami models are displayed for your model. People will often add the paper type and weight to the model's description and this can help you choose paper for your own folding. When you buy online at a specialist origami store, you can also ask the shop about particular paper's suitability for certain kinds of models. No one can guarantee you a good fold (it depends very much on your own work), but they can give you hints which paper may be good and which you should avoid.

Ilan Garibi has a series of paper reviews on OrigamiUSA where he has reviewed a number of commercially available papers. I have found these reviews to be very helpful when I started to get interested in origami papers myself.

Finally, here are some properties of the paper you should look for. Generally, you want your paper to be thin, yet strong and crisp. In more detail, this means paying attention to:

Paper weight, usually expressed in gsm (grams per square meter). These values are only approximate ratings but they give you an idea of how thick the paper is. 80 gsm is the weight of standard copy paper and is too much for many complex models, for which you should look for 40-60 gsm paper. Some very fine papers used for insects go as low as 20 gsm. Elephant Hide, a thick and stiff paper, is rated at 110 gsm. Papers around 160-300 gsm are suitable for wet folding but hardly foldable dry.
Fibre types: hand-made papers have long fibres which is usually a good thing. Longer fibres make the paper stronger and make it behave better when you need to wet fold some detail.
Crispness: it should be possible to make a sharp, well-defined crease at exactly the place you want it and paper should hold the crease well. This is especially important for complex folds like sinks where you precrease a line and then collapse along it. Soft paper has its benefits too, but too soft may make folding difficult.
Aging: one of the reasons I started using better papers was I noticed I had to throw away a number of old models which had faded and become very ugly. If you invest a lot of time into folding a complex model, you want it to stay looking fresh for a long time. Chlorine-free and acid-free papers are expected to last longer than those with the extra additives. Hand made papers often avoid these chemicals and age quite well.

The first paper review by Ilan Garibi describes these and many more properties which affect how origami paper behaves when you fold it and which make it suitable or not for particular model types.


Efficient cutting and preparation of fabric for sewing clothing

I would hesitate to cut my fabric into smaller pieces for storage, just because I can pretty much guarantee that as soon as you cut your fabric, the universe will send you the perfect pattern for that particular piece of fabric--but the pattern will require about 1/2 yard longer than your chosen cutting length.

But the reason I wanted to post an answer is because I just took a sewing class where my instructor insisted on teaching us how to cut fabric when you only have a small cutting surface.  The basic tenets were that you should NEVER let fabric hang over the edge of the table, as this can pull parts of your fabric off grain.  Instead we spent a lot of time folding and refolding unused and/or already pinned sections of fabric as we laid out our patterns in preparation for cutting.


Prevent repositional glue from sticking?

One thing that might work to reduce but not prevent sticking is sticker backing paper (waxed/plasticised). Unfortunately it's rather obvious, and not easy to attach because it's designed not to stick to glue.

Another hard to attach (I suggest staples) material is reusable non-stick cooking liner.  It's normally brown similar to much packaging cardboard, but can sometimes be found in black.  This again won't completely prevent sticking, but will make removal much easier.

These won't damage the sticky layer on the card, while one thing that probably would is wiping a very thin layer of oil/cooking spray/silicone furniture polish over spray lacquer.  This approach has the advantage of being applied like a coating, but could end up messy as well as spoiling the glue


Are acrylic painting tutorial videos different from oil painting videos?

Yes - Acrylic and oil paints create different effects on the canvas, they are blended differently, and they dry at much different speeds.

Acrylic painting techniques are different styles of manipulating and working with polymer-based acrylic paints. These types of paint eliminate the need for turpentine and gestapo, and can be applied directly onto canvas.

Here are some tips for ** Oil Painting**.


What kind of dye or paint for t-shirt design?

Do you want the shirt to actually be wearable? If so, then "synthetic resin varnish" is entirely the wrong option.
For wearable clothing, you need a color that bonds with the fibers to endure wear and washing, but also remains soft to allow for comfortable wear. The best option for something like this would be a standard acrylic paint with a high opacity mixed with a fabric medium. The paint will provide the color, the opacity will allow it to stand out brightly against the black background, and the fabric medium mixed correctly helps the paint bond with the shirt's fibers instead of sitting on top. You could also use a dedicated (pre-mixed) fabric paint, which is often available in brighter opaque colors. Both these options are widely available at craft stores.
An additional option for adding designs to shirts is silkscreening ink, but fewer opaque pigments exist (bright colors on black are usually a double layer printing with an opaque white base). Because you're looking for bright colors in a splashed pattern, this is less likely to get the result you're looking for.


How to drill a hole on diecast toy using dremel?

For delicate work in soft materials, I still like to use my old wheel brace (hand drill).  I've used it on plastics, wood and aluminium when I don't want to risk marring the surface as I break through.  Securing the workpiece is an absolute requirement as it's a two-handed tool.  I'd start with a 2 mm drill bit, then use a 4–4.5 mm bit so you've got the minimum at the next step.

You could then square off the corners with a needle file.  My square needle file is about 2–3 mm at the widest point. This will give you much squarer corners than any rotary tool can provide.  Even if you start with the dremel, you may need to finish off with a needle file.


Steel weighs 8000 kg per cubic metre, or 8 kg per litre.  A US gallon* is 3.79&nbspl, so a gallon of steel weighs 30 kg or 66 lbs.  Unless you buy it in one piece you won't get perfect packing but you'd only need a 37% packing fraction to fill that gallon.  Identical ball bearings should get more like 60%, but ball bearings aren't cheap.  Old nuts and bolts would work if you can get them cheap.

At this point though, your milk bottle wouldn't survive long - it isn't designed to take the weight - so you need a stronger container, or to fill it first with steel then with epoxy (including the handle) effectively using the bottle as a mould.  That much epoxy would add  another couple of kg (~4 lbs) and could get expensive (though there are cheap types ).

Wet sand would actually only need 1.5 gallons to reach 25 lbs. Sand-filled epoxy would be similar to wet sand - you'd need to mix it well in another container, using just enough epoxy to fill the gaps in the sand.  This is strong.

* Apparently a common size for plastic milk bottles in the US


The "rubber" eraser you linked to actually looks like a plastic eraser.  "Rubber erasers" typically refer to the type on the end of a wooden pencil or a block like the Pink Pearl eraser.  There are many other types of erasers; I'll focus on just the two in the question.
Just an interesting historical aside, the first erasers were made of rubber but the "rubber" in "rubber eraser" comes from the fact that when erasers were invented by accident in the late 1700's, the term "rubber" was in common use for any object used for rubbing[1].
Rubber erasers aren't usually made from natural rubber any more.  They're a rubbery plastic or synthetic rubber that contains a lot of plasticizer and some abrasive filler material, the amount of which varies.  Rubber erasers are generally good for pencil lines, although the surface can get saturated with graphite and then start smearing it around.  Decades ago, ink erasers were rubber erasers with more abrasive.  They were harder and erased the ink by sanding away the paper surface.
Plastic erasers are a soft, rubbery plastic, often vinyl, with no abrasive filler.  They are generally better than rubber erasers for most purposes.  They erase pencil marks more effectively and with less tendency to smear.  They can sometimes remove ink marks without tearing up the paper surface.
I've come across articles like the quote added to the question, that claim plastic erasers are hard, or they more easily tear the paper.  I've used them for probably decades and have no idea where those claims come from.  Plastic erasers are more effective and require less pressure and rubbing.  The paper is more likely to be damaged by using a rubber eraser that smears the pencil marks, then requires more aggressive rubbing to clean it up.
The plastic erasers tend to be more expensive than the rubber erasers.  It's possible that they are more expensive to produce, but I suspect pricing is based on what the market will bear and the size of each market.  Rubber erasers are adequate for school and a lot of general office and personal use.  Plastic erasers are more in demand for more critical applications like art and drafting, where users will spend more for better performance.
Buying single erasers often carries a huge price markup that has little to do with the manufacturing cost of the eraser.  If you buy packages of three or more, or especially, a bulk box of 10 or 12, you can often get a lot of erasers for what you would spend on a couple of individual erasers.  Even if it takes you a long time to go through them, the initial purchase won't break the bank.
I'm not sure of the monetary conversions for the prices in your links.  Looking at prices in the US market, you can easily find packages of two or three rubber erasers at around $0.50 per eraser.  In-store at a retailer like Walmart, you can get a package of two for less than $0.50.  For the plastic erasers, you can find bulk packages of 10 or 12 at $0.50 per eraser, like these brand name erasers through Amazon.


Hand Sewing Patch to Huge Elbow Holes in Sweater

This is what I would do:

Take the thread and whip stitch the holes so they do not fray any
further.
Since it is knit textile, tighten and loosen to manipulate the hole
in a fun or fashionable shape.
Place the patches on the inside of the garment, temporarily secure
with safety pins, straight pins or basting stitch.
Use an interesting embroidery stitch to secure the patch permanently.
Remove pins or basting stitches.
Trim excess fabric.

A fun alternative is to appliqué over the holes:

Whip stitch the holes to prevent fraying.
Secure patch on the inside with pins or basting stitch.
Cut out an appliqué shape or shapes, secure to “right” side and
stitch.

Key words/ phrases to search for:

whip stitch or blanket stitch - used to quickly sew an edge
basting stitch - long & loose stitch to temporarily hold materials together
appliqué - technique to apply cut fabric designs onto material
knit textile versus woven textile

FYI: darning has been addressed in the Stack Exchange, but mostly for woven fabrics, not knits.


What kind of paints should I use to color / paint on bright wood material?

For natural wood that you want to look like wood, think staining, not painting.

To make that chest look like an old, beaten-up treasure chest, get two colors of stain: one medium-toned one, such as maple or chestnut, and one darker one, like dark walnut or maybe even ebony. For such a small box, you won't need much stain, especially of the darker color, so see if you can get sample sizes. You'll also need some good varnish or polyurethane, not too glossy.

First, stain the whole box with your lighter stain, following the instructions on the package.

Once that's dry, add some realistic-looking damage or weathering: drop the box on its corners a few times to dent/round them off, get something hard and heavy and drop it on top of the box to add dents and gouges, etc.: get creative, but not too creative.

Now, use the dark stain to add "dirt": rub the stain over the box, then immediately wipe it off, but don't do too good a job. The dark stain will remain in the dents and gouges, but not on the surface. Leave more dark stain along the edges and around the hardware. Use a toothbrush to flick stain onto the box to imitate mildew spots. Look up some pictures of the type of old chest you're trying to imitate to figure out where the "dirt" should go.

Once the darker stain has dried as well, and you're reasonably satisfied with how it looks, finish the box with a varnish or polyurethane coating. This is what will make it durable; it will also deepen the colors of the stains. If the result starts looking unrealistic, wait for the varnish to dry, then basically sand it off (or mostly off), adjust the stain, let dry, and varnish again.

If you want to reproduce the metal strapping of the classical "treasure chest", you have several options.

Option 1, you can get what's called "tooling foil" or "embossing foil" at the craft store. It's basically like aluminum foil, only much heavier than even the heavy-duty foil you can buy for culinary purposes. However, it's still light enough that it can be pretty easily cut with ordinary scissors (well, OK, so don't use your nice Gingher fabric scissors - steal the kids' craft scissors instead). To use it, cut out strips in the shape you want, and glue or nail them to your box. You can then use your wood stain to give the metal a more distressed finish. If the stain doesn't seem to be sticking, rub the metal with steel wool to remove the protective finish, and then try again.

Option 2, you can try doing the same thing as option 1, just using ordinary heavy-duty aluminum foil and glue. You can even spray-paint the foil with brass-colored paint. The advantage of this, besides being cheaper, is that the thickness of regular aluminum foil is more in proportion with your small box than the 36 gauge stuff, so you can go ahead and, say, wrap the edges of the opening in a realistic-looking manner, without danger of preventing the box from closing properly.

Option 3, you can get some brass-colored craft paint and paint on the strapping. Do this after staining but before varnishing, and then varnish everything once both the stain and the paint are dry.


How long should I wait for watercolor pan activation?

After you add water to the pans you should agitate it a bit with the brush to get more color into suspension. There is no time delay, it is just a matter of how much pigment gets mixed with the water before you apply it to paper.


How much noise does an airbrush compressor make?

Your question is almost impossible to answer, since we don't know how much noise will disturb your family (small baby sleeping? kids running around? partner concentrating on a difficult math problem?). But normally the sound level is shown on compressors and here is some references to help you imagine how much it means:

0dB Weakest sound heard
30dB Whisper Quiet Library at 6'
60-65dB Normal conversation at 3'
80dB Telephone dial tone
85dB City Traffic (inside car)
90dB Train whistle at 500', Truck Traffic
95dB Jackhammer at 50'
95dB Subway train at 200'
90 - 95dB Level at which sustained exposure may result in hearing loss
98dB Hand Drill

Source: The Relationship of Voltage, Loudness, Power and Decibels
You might also be interested in this article on quiet compressor: Quiet Air Compressor – Some Facts You May Want To Know


How should I fix a large mirror ball with many cracked mirrors?

See if you can find some adhesive vinyl with a mirrored surface.  I had some a few years ago and it was every bit as reflective as the individual squares of a mirror ball.  The material is meant for use in a cricut or silhouette brand vinyl cutter and is probably sold at your local art supply store.
Cut the vinyl into squares the size of cracked mirror squares then peel off its wax paper backing and stick it over the cracked squares.


While not impossible to open without tearing, and requiring cuts as well as folds (which disqualifies the method as origami to an origami purist), there is a form of letterlocking that involves cutting a thin strip from the blank margin of the letter, folding the letter, and then punching holes through the letter with an awl, and threading the strip through the holes in an interlocking knot-like pattern, which would make it very difficult to open the letter without tearing the thin delicate strip of paper.

See: https://vimeo.com/189348055

http://letterlocking.org/categories states that this blank margin method of letterlocking was "used by Queen Elizabeth I of England, Mary Queen of Scots, Catherine DeMedici, and many others."


Is it possible to drill a CPU cleanly with a plasma cutter?

Use a diamond drill bit. Cheap plated bits are good to learn on, but if you're doing it a lot, invest in sintered. Look at a lapidary or jeweler supply store/site or eBay


Need advice on a color that matches this color theory

This is based simply on classic color theory:

You're currently using two colors, and want to add a third. So, using color theory would involve choosing the third color based on the relationship of the first two to one another.

Since the coral orange and dusty purple (based on my screen) are about 1/4 of the "wheel" away from one another, there's really two color schemes that fit:

Light, lime green fits in with a triadic color scheme.
A rose pink could fit in quite nicely with an analogous scheme.

Triadic color schemes have 3 colors that split the color wheel into equal thirds. Closely related is the split complementary theme, where two of the colors are adjacent to the complement of another. In my example, you'd be using a blend of both. Your first two colors aren't so close together that the complement of the lime green, rose pink, is actually adjacent to them. That's why it's more of a triadic color scheme, despite not being a perfectly even split around the color wheel.

The analogous scheme is using three colors that are near each other, the "outer" two (on the wheel) about the same distance from the center color. That's how I arrived at my rose pink suggestion.

It's important to remember that there's room to play, and color theory can be used to develop rich palettes with many distinct colors, even if it's only three base colors from the wheel. And the color you pick can affect the mood or tone you're trying to set in your work. Consider the difference it would make shifting the lime green closer to yellow or green. Or making the light green even lighter, or darker, which would add contrast of brightness.

Here's a quick example palette with the four colors discussed (roughly), as generated from the link I provided to Palleton (a simple interactive color wheel with built-in scheme options).


Best way to attach EVA decals onto a stretchy synthetic fabric?

The comments are all good - and in answer to your question "Will glueing a non-stretchy piece on stretchy fabric cause tearing?" the answer is most likely yes, or at a minimum, it can cause "runs" (torn yarns that pull through the bodysuit fabric).  Also, when the bodysuit fabric stretches, the glued decal might just pop off.

Your potential decal materials from foam, iron-on, and faux-leather will behave quite differently from each other.  The foam will have some stretch, the iron-on and faux-leather will have no to very insignificant stretch.  You may need different attachment mechanisms for each type of patch.

Even if your decals are stretchy (e.g., thin foam), they may not have  have the same stretch factor and in the same direction as the fabric of your bodysuit.

Two ideas:
One thing that might work is to adhere the decals with spots of glue or a few tacking stitches (one stitch tied off),  sort of like spot welding.  This will still allow some stretch of the suit fabric underneath.  The fewer attachment points the better to allow for base-fabric stretch, but the more attachments points you have will probably look better.

Another thing to try would be to loosely attach the outline of the patch with running stitches using clear elastic thread.  Use as few stitches as possible to still achieve the look you want.

Running Stitch
https://www.thespruce.com/working-the-running-stitch-1177571

Clear Elastic Thread
http://www.michaels.com/clear-elastic-38-x-5-yards/D010864S.html?mkwid=s9ha3UAHp|pcrid|221603638463|pkw||pmt||pdv|c|prd|D010864S&cm_mmc=zadv_PLASearch--google--sewing-and-fabric-_-sewing-and-fabric-sewing-and-quilting-notions-elastic&utm_source=google&utm_term=&utm_campaign=sewing-and-fabric&utm_medium=cpc&utm_content=s9ha3UAHp|pcrid|221603638463|pkw||pmt||pdv|c|prd|D010864S&gclid=EAIaIQobChMIyYLx8uWx1wIVhGx-Ch2yIgrmEAQYBSABEgL64PD_BwE

Good luck!  Let us know what you try and how it works out!


Is there a difference in stability between prestringing and placing a bead?

There are a lot of pros and cons to both methods of placing beads into your knitting, but when looking only at stability there is a difference between prestrung and placed beads. Having used both methods, I find the placed beads stay precisely where you put them whereas the prestrung beads can slip.

When you place a bead you put it on precisely the stitch required. It can't shift anywhere because the two yarns going through it split and go in different directions. When you knit a prestrung bead into your work, it can travel along the yarn. Generally this means if, for example, you place the bead on the vertical leg of a stitch, it could slip up or down to rest on the horizontal bar of the stitch. This sometimes means it slips to the back of the work. The looser the gauge, the more this problem will occur.


How do I get my Envelopener to cut cleanly every time?

I use envelopeners a lot and indeed prefer them to any other means of cutting paper in almost all cases. Here are some tips from my experience:

Regarding the cutting tool itself:

First of all, envelopeners are consumables: they will become blunt over time and there's not much you can do about it. Since they are cheap, simply replace them once in a while, especially if you start running into issues more often than you used to. Your mileage may vary depending on how often and what types of paper you cut, but mine last less than half a year.
The blade which sits inside the tool is pressed between two halves of the plastic case. You can open the case by inserting a fingernail or a screwdriver blade into the narrow gap between the two halves. This will allow you to:

Clean the blade from paper residue which gathers around it. Some envelopeners have a shaft which is supposed to allow the lint to escape from the blade but this does not always work perfectly.
When closing the case, press the two pieces of the case firmly together. Sometimes the two halves become a little loose, causing the blade to not be mounted in a fully symmetric manner, which can cause both parts of the paper to move around a single side of blade instead of getting the blade exactly in between them.

As for the cutting technique:

The envelope opener works best if the crease along which you cut is perpendicular to the paper edge. So, it's good for cutting squares but much worse for cutting hexagons. Personally, I use a Swiss Army knife or scissors for cutting hexagons since the envelopener doesn't handle them well.
Sometimes you run into problems such as splitting the sheet into layers instead of cutting along the edge when trying to cut thick paper and the crease along which you cut is pressed too firmly (e.g. using a bone folder). So, sometimes it helps to either not make the crease that sharp, or to fold it in the reverse direction after folding, which also results in a somewhat less sharp fold.
As mentioned above, an envelope opener consists of two plastics casing parts with the blade fixed in the middle right between them. These two halves of the case do not always perfectly fit together and there may be a small gap between them. Sometimes when you start cutting, you may press the paper too deep inside the casing, which causes the creased part of the paper to get stuck in this narrow gap. The solution is to check that you are not inserting the paper too deep.

While these tips do not guarantee a 100% success rate, and I still occasionally make a bad cut, I think that I have become better at using the envelopener over time, so I hope they are helpful for others, too.

UPDATE: I summarized these tips and some more in an article on my homepage


How to chose between soldering and welding?

For the benefit of other readers, let me start with a brief explanation, and I'll expand the terminology to include brazing.  Soldering and brazing are the same process, the difference is the temperature at which it happens.  Both involve using a filler metal that melts far below the temperature of the base metal to be joined; when this process happens below 842°F it's called soldering, above that temperature it's called brazing.
Welding
Welding involves melting the base metal so the liquid metal from the two pieces to be joined flows together.  Additional metal of the same kind can be melted and added as filler.  This creates a single, solid piece of the base metal.  The strength of the joint will be determined by the amount of metal there and how the "heat treatment" of the melting process affects it.
If we ignore spot welding for this discussion, where sheets of metal are overlapped and then melted together at small spots, welding is typically an "edge" process.  Pieces are butted against each other and the edges are melted together, or the edge of one piece is melted to the face of another piece.  Welding typically takes place on an exposed surface, and strength is achieved by filling or building to create the desired thickness of metal.
Soldering / Brazing
Soldering and brazing are a bit like hot gluing metal together with other metal. Metal with a melting temperature much lower than the base metal is melted and used like glue to stick the base metal pieces together (done by heating the base metal to above the melting point of the filler metal, and that melts the filler metal).  The solder or brazing material forms a metallurgical bond with the base metal, but it doesn't have the mechanical strength of the base metal.  So you can't butt two pieces of base metal together, connect them with some solder, and expect the solder to perform as if you have a solid piece of base metal.
Solder and brazing joints rely on a different principle.  The mechanical strength comes from the base metal; typically, two pieces of the base metal overlap and a thin layer of the solder or brazing material between them keeps them from sliding or pulling apart.  The liquefied solder or brazing material flows over the base metal surface in a thin layer through wetting the surface and flowing as a liquid, and by being drawn into gaps via capillary action.
The strength doesn't come from the filler metal.  The filler metal is typically just a few thousandths of an inch thick.  The strength comes from a large surface area, where the stresses are trying to shear a lot of filler metal the "long" way, or trying to pull it apart across a large surface.
As Chris H points out in a comment, brazing can also be used for some welding-style joints.  If you use a filler metal that has mechanical strength and melts below the temperature of the base metal, it can be melted and built up around the joint so that the filler metal is providing the mechanical strength of the joint (called "fillet brazing").  In this case, the strength of the joint depends on the mechanical properties of the filler metal, how thick it is, and how much area of base metal it's bonded to.
When to use which
Both approaches can have similar, or at least adequate, strength.  Ignoring the fact that welding takes specialized equipment and more skill, there are a number of considerations that go into the choice of approach.

Nature of the joint.  As described above, the type of joint may point to one method or the other.  For example, if you need to butt two edges together, soldering/brazing generally won't be a good solution.  If you need to join two thin nesting tubes and ensure the joint will hold liquid or gas under pressure (think copper plumbing or refrigeration systems), welding is not a good solution.

Strength requirement.  If strength is a critical factor and the joint needs to have at least the same strength as the base metal, some joint configurations may require welding.

Size.  Soldering/brazing requires heating a large surface to above the melting temperature of the filler.  Two massive metal base pieces may conduct heat away too fast for soldering/brazing to be practical, or to evenly heat the entire joint.  Welding uses very localized heat, so large pieces can be joined with a series of welds.
At the other size extreme, welding is too crude.  For a weld to have useful strength, it needs to involve a substantive amount of metal, and the melt area will be large enough to readily see.  Welding isn't typically suitable for something like assembling jewelry components.  The melt area will visibly affect the shape of the piece.  And if you need to fix the shape by grinding the weld, you're often wasting precious metals.  So jewelry-making normally uses soldering.

Material to be joined.  The heat required for welding might distort the pieces to be joined.  Thin material can melt and flow away from the surrounding material, destroying the shape or integrity of the material.  Soldering or brazing keeps everything below the melting temperature of the base metal.
The type of base metal may introduce considerations.  Soldering or brazing requires use of a filler metal that will wet and bond with the base metal.  At welding temperatures, some metals quickly oxidize, so welding may require use of special equipment that keeps the molten metal in a chemically inert atmosphere.

The need to join dissimilar metals.  Soldering and brazing allow you to join two different base metals, which you can't do with welding.

Post-joining requirements.  If the joined pieces might ever need to be separated, soldering/brazing would allow that (e.g., reworking copper plumbing).  If the joined pieces might be exposed to high heat, either in subsequent fabrication steps or the environment in which it will be used, welding might be required to prevent the joint from falling apart.

Appearance and cleanup.  Welding typically doesn't leave a nice finished appearance.  If appearance is important, the joint usually requires grinding.  If soldering or brazing leaves excess material, it is easily melted so it self-levels or can be wiped away.  It is also typically softer than the base metal and is easily abraded in a controlled way to give it a finished appearance.

Industrial process.  In an industrial or mass production setting, there can be considerations of speed and cost.

These aren't all of the considerations, but it will provide a flavor of the decision factors.


How can I convert a V-neck shirt to a square neck?

I recommend that you ignore the depth of the V in your v-neck shirt and cut the square where you want it to be (allowing for seams, obviously). Then, using the cut-out material, you can use it as a modesty panel to fill in the space where the tip of the V is to make a full square neck.

What you do with this notch is up to you. You can try to make it blend in by stitching it flat or you can use some of your embellishments to make it an accent to the center of the square.

The final result would be something similar to the neckline here:

Though, I'm guessing the V left over is going to be shallower than this one.

The obvious benefit here is that you don't have to muck with how the shirt fits. It's not been recut. All you've changed is the neckline.


How can I resize this crocheted hat pattern for an infant?

First of all, you need to figure out your gauge (sts & rows) using your #5 hook and the yarn you want. Using your baby inches, see how far off you are from the pattern. Use that as a rough ruler for following the pattern. You'll need to keep to an even or odd # of sts in your baby length, but also notice the group sts and how many sts they take each so you'll have the right # of sts to work into. Does that make sense?

To begin with, I would suggest you reduce the # of rows in the band, so it won't be 1/2 of the hat unless you want to make a cuff with it. You'll have to keep track of the rows so you'll know when to start a new one and when to decrease.

I can't tell you exactly how to decrease without dealing with the pattern and your gauge. I suggest you see how the first several rows after the band shape up and look at how often the pattern suggests dec. It's not the end of the world if you have to take out a row or 3. It should be pretty quick work; it's not a complicated pattern.

I hope this has been some help. When I increment or decrement a pattern, I just have to wing it beyond a certain point. As I said, taking out some rows won't take long to re-do.


Curtains lined with the same material: where should I put the seam?

If you will mostly view the curtain from one side, handle that as the 'side you look at in normal curtains', do have that side a bit bigger and fold the edges over to seem them.
On the other hand, if you will see the whole of the curtain from both sides and you will want both to look nice, two pieces of fabric the same size, put the good side on the good side and sew around the outside, I would leave either the top or the bottom open for now. Turn and top stitch just inside the edge.
Most likely you will do something in the top seam to hang the curtain. If you have the skills to do that with the two layers of fabric finishing it nicely at the same time, keep the top open.
Otherwise, close the top and keep the bottom open and 'only' top-stitch that closed. (You can even seam both sides individually and leave them open at the bottom, your call, if will fall better but is more likely to get out of shape.)
If the side seam is shorter or more out of sight you can use that as the last instead. You can play around quite a lot, as nobody but you will judge your quality of work.


What type of paint should I use for stone painting meant for outside

What you need is exterior masonry paint.

Which specific kind of exterior masonry paint may depend on what sort of stone you're using. This page from a decorating advice site tells you which kind of paint to use in which context. It's written from the point of view of painting walls of a building, but some of it may still be useful to you.

In particular, mineral-based or lime-based paint should fit your criterion of being eco-friendly, and limewash looks like the best choice for your situation: it's simple to make, relatively cheap, looks natural, and is eco-friendly. The following quoted text taken from the above link even provides you with possibilities for where to buy it:

  Mineral Based Exterior Paints

  Put simply,  mineral paints are made with a silicate binder which reacts with the surface of the wall to form a long-lasting bond, unlike traditional paints which simply form a skin. They are naturally alkaline, so inhibit mould growth and carbonation; mineral paints also have the added advantage of being eco-friendly too.

  The disadvantage is that they require more thorough preparation, special primers and are, initially, much more expensive – although the increased performance should pay back over the long term.

  There are a few specialist manufacturers of mineral based paints – the main two being Keim and Beeck.

  Each have their own detailed specifications for different kinds of wall surface and these must be followed to the letter in order to enjoy the maximum performance.

  Lime Rendered Walls

  For old buildings with a lime based render or lime based pointing a traditional Limewash is ideal. Limewash is simply a paint made from lime powder and water together with a colourant.

  The main advantages of limewash are they bind to the surface very well and are totally breathable – another benefit is that they are relatively inexpensive.

  Care needs to be taken with application and sometimes additional binders need to be added to aid adhesion.The finished result can be very striking though – looking much more natural than a traditional paint finish.

  Limewash paints are available from a number of sources including Ecos, Ty-Mawr, Little Greene and Farrow & Ball.

  ECO Paints

  Technically, an ECO paint is simply a paint which has a very low or zero volume of Volatile Organic Compounds. While some ECO paints are obviously superior to others there isn’t any case for suggesting that an ECO paint will perform any better or worse than any other form of exterior paint – it will simply be a matter of personal choice.

  It’s worth noting, however, that mineral and lime based finishes, mentioned above, are by their very nature eco-friendly – so would make a good choice if you wanted to be as environmentally friendly as possible?

I also found detailed instructions on how to repaint a gravestone. They recommend using oil-based paint, assuming a granite headstone. If you're thinking more along the lines of smaller stones or pebbles, then this site recommends using acrylic paint, with a sealer on top at the end.


What you're talking about isn't just one style or school, but it sounds like you may like works coming from: scuola metafisica, surrealism, American modernism, American realism, expressionism, and symbolism.

Now, as I said, the characteristics you described don't define any school of fine art in particular, so within those schools there will be works that do and don't fit what you're looking for.

Definitely check out Egon Schiele and Giorgio de Chirico.


Why do artists use pigments instead of dyes in paintings?

While more historical artists likely didn't understand the chemical processes behind the behaviors of the two options, the biggest reason is permanence.

Dyes are organic substances that are either soluble in their medium or in their application. This means the structure of it breaks down as part of the application. The structural breakdown, coupled with the organic state is ultimately why dyes are less permanent.

Pigments may be organic or inorganic, but do not break down in their binder or application. Because the structure of the pigment remains intact after application, their application is more permanent assuming it continues to adhere to the surface of the support.

I'm sure that a fair number of artists initially tried dyes over pigments, but in time the knowledge of the behavior differences would have spread from teacher to student. For practice, many may have chosen dyes, but when it came to important works, not likely. Bearing in mind that the expense of many pigments was often born by patrons of a number of the artists, so quality was very likely more important than cost.

It's also worth noting that the extremely expensive pigments, such as lapis lazuli used to make ultramarine, were often reserved for the most important of subjects such as very wealthy nobility or religious works. Less expensive pigments would be mixed for close approximation in other cases.


My Mod Podge coat is still sticky. What do I do?

Mod Podge takes a very long time to cure; around four weeks, depending on humidity and coat thickness.

To properly use Mod Podge, you need to apply multiple thin layers (not thick ones), allowing them to dry completely between each coat. According to Meaningful Mama,

  If you don’t let [the Mod Podge] dry completely between coats, your project can end up more sticky and may bubble a bit.

"Dry" is not "cured," however; while it will only take an hour or so (again, depending on humidity) for each coat to dry, you need to leave the pieces alone for roughly a month to become fully cured and hardened. Once fully cured, the Mod Podge will be a durable coating resistant to damage, but during the cure time, it will remain soft and susceptible to damage, including shifting and peeling.


It is possible to blend using markers, though like any new medium it can take some practice as well as depend on the type of marker you're using.

Water-based markers

Blending water-based markers requires little to no additional special equipment, just some water and a way to apply it. As you mention experience with watercolors, this may feel fairly intuitive to you. You'll use either a standard brush or a water brush (a hollow brush pen that can be filled with water) to apply water to your paper and fade or blend your colors. Additionally, you can use a non-porous surface to build up some ink from the marker and use it very similarly to paint by picking the ink back up off that surface with your brush/water brush.

The blog The Frugal Crafter has an entry showing a wide variety of samples of both test blending and artwork done using inexpensive water-based markers and brushes to blend.

Brands include Tombow, Marvy LePlume, Crayola, Mr. Sketch, etc.

Alcohol-based markers

With alcohol based markers, the key to blending is to work while the ink is still wet; this can mean working quickly from one color to another on the page, touching the tips of two markers together, or applying one marker to a nonporous surface and picking the color up with another. Additionally, many brands feature a "colorless blender" pen that contains only the solvent and can be used to help fade a color into the paper's color.

User Khallandra on DeviantArt offers a nice rundown of various blending techniques with a large number of sample images.

Brands include Copic, Prismacolor, etc.

Solvent-based markers

Solvent-based (xylene, etc) markers may behave fairly similarly to alcohol-based markers, and even may include the option of a colorless blender for them. Their blending is not as smooth as that of alcohol-based markers, however this may vary to some degree by brand. I'll note that while I personally have used them in the past, it was briefly and some time ago due to the heavy fumes released by the solvents, which can cause eye and lung irritation.

The Curiously Creative blog has a guide to general marker types, which has the best general, neutral information I could find on solvent-based markers.

Brands include Sharpie, Chartpak, etc.


Some pigments used in inks are UV sensitive and disappear rather quickly when exposed to sunlight, others remain unaffected. Having in mind the colours you need, make some research about which pigments are used to make your desired colours and which of them are UV sensitive and which are not.

Check what water-based products are available on the market and if you can figure out which pigments they use (they are likely to be written in their catalogue which are generally available online) go for the ones you have found out that are not UV sensitive.

Alternatively, you can buy ground non-UV sensitive pigments and learn how to make your own watercolours (follow the health and safety instructions of the tutorials, as some of the pigments are toxic).

Since your problem is the UV light, if you want to use varnish, etc to preserve the colours you should look for something that would acts as a UV filter (without affecting your drawing).

Also, you may want to consider using oil-based markers instead of alcohol-based ones. They may do a better job at keeping your outline drawing ink/watercolour-free.


How to lubricate toothpicks for model building?

Try bar soap or silicone spray. Soap is definitely slipperier than wax and you likely have some on hand.

Silicone spray is super slick and useful in lots of situations. It will stay slippery longer than the soap which may be a problem if the pin is supposed to stay put once its in.

Maybe a bit of sanding with fine grit sandpaper would help as well, corrects oversized pin and smooths the surface for less friction.


Since fire coats the things it can't destroy in black opaque soot, it doesn't really matter if the colors underneath survive... they won't be seen until after someone cleans the sign, after the fire is over.

I would suggest using the sign's shape to convey its meaning.  That way, even when it is totally blackened and silhouetted against a wall of flames behind it, its meaning will still be clear.

As for material suggestions, I would consider aircrete ( a mixture of concrete with a foaming resin ) which is extremely fireproof.  Also, there are a lot of additives that you can add to concrete (and by extension aircrete). Gypsum or Quartz powders will make the sign reflect flashlight beams. Dyes and colored stones can be added to increase the sign's unsooted visibility and some to those dyes absorb sunlight and glow in the dark.  The sign can either be made relatively attractive or garishly noticeable with very little additional effort.


How to add paint to the bottom and stain/varnish to the top of a wood project?

I have crossed this situation where clients want to stain their banisters and paint the spindles. In such cases, we stain first, then tape off the banister and paint the spindles.

Note: You can stain (light colors / not solid) over paint and it will adhere, giving it an antique look. Example photo below of stain over paint.


Where can I get brown packing paper mesh?

When I want larger volumes of packing material, I tend to look to two sources:

Self-storage facilities. A lot of these places offer boxes and other packing/storage material and may offer cardboard options as opposed to traditional bubble wrap.
Self-moving companies like U-haul, amongst others, who can supply a lot of the basic packing and storage material for a move.

Beyond that, office supply like Grand & Toy, Staples, etc. would be next on my list. Actually, given some convenience, they might be first. :)


Casting Elastomers as Acoustic Insulators

Dampening is actually more complicated than what you're asking.  It isn't simply a matter of using a material that dampens vibration. It's a function of the frequency you want to dampen. You will dampen some frequencies, but amplify others, and can get resonance that's more problematic than having no damper at all. If the dampers will be supporting weight, you also need to consider things like how the compression will affect it.

There's actually some physics involved in designing dampening to do what you want.  If you don't have access to a physicist or engineer who deals with this stuff, your best approach would be to play with different materials, sizes, etc., to see what works best for your application.  Another option would be to use commercially available dampers that have been designed for your application and that users have said works well.


How do I evenly space my knots for my hanging craft project?

First thing that comes to my mind, why don't you try it in the same way as bobbin lace? In your case, that means a large cushion (maybe a(n old) mattress), as stiff as possible, and use pins to get/keep the knots in the right places.


How to do iron-on transfers on a softshell jacket

Below is a pretty good definition of a soft shell jacket - imo I think of soft shell jackets as anything not waterproof like with a Goretex finish which could (1) be damaged by heat, and/or (2) resist application of the transfer. Most important for you, though, is that they are almost always made of synthetics which can melt from high heat (i.e., from ironing).

Your best bet would be a cotton/synthetic blend, no high-performance finishes, and be sure to test with an iron on a place inside the jacket that no one will see.  Good Luck!

Soft-shell Jackets are designed for use outdoors as part of the layering system, and can be used alone, ideal for aerobic activity in light weather conditions if they are water repellent and highly breathable, or as an insulating layer under a 'hard shell' outer jacket.
Guide To Soft-shell Jackets - GO Outdoors
www.gooutdoors.co.uk/expert-advice/softshell-jackets

from:
https://www.google.com/search?client=safari&rls=en&q=what+is+the+definition+of+a+shoft+shell+jacket&ie=UTF-8&oe=UTF-8

Edit/Additional Information:
The 741 customer reviews & 202 answered questions in the product information link you provide in your question for Avery iron-on transfer papers have a wealth of information and tips for using (or not using) this product. I suggest reading all of them if you haven't already.

As mentioned in the first posting of my answer, ironing temperature is a critical element to success and requires some experimenting with the heat settings on your iron and the exact fabric/fiber type of the jacket.

My experience with these type of transfers is with kids'/teens' tee shirts, in 100% cotton or "cotton rich" blends which means mostly cotton with some low percent if polyester (under 50%), or stretch fibers (under 10%), like Lycra.

Kids' tee shirts are not a big initial investment and they usually only need to get through one party or school event, and the result doesn't need to be perfect.  This is not the case with a nice jacket, so the stakes are higher for you.

The potential issues I see with your project are:

You are not sure what the fiber and fabric type of the jacket will be
You won't have extra fabric to test the transfer papers on
The jacket will likely be an investment and it could be ruined

I know you like the idea of the transfer papers, and they are cool.  You might want to buy some fabric and play around with the papers and the process before working on a jacket.

If you aren't able to access or use a professional apparel printer who can upload your design and print the jacket for you, you could also look into professional embroidering businesses in your area.  Commercial embroiderers can also use your uploaded design file.  A complication with these options is that you usually need to print/embroider a certain number/lot of items to make this financially feasible.

One option for you that is less costly and will still let you use the transfer papers, is to purchase some fabric at a fabric store and print on that.  Then cut the printed image out and attach it to your jacket by sewing or gluing with fabric glue.  If you try this, it would be best to buy your background fabric in the same color as the jacket, and made of  approximately the same fiber content and fabric construction.

At a minimum, you could buy one package of the transfer papers and practice on clothing you already have that you can either live without, or live with if the printing isn't perfect.


How can I get children's paper masks to last longer?

For reinforcing your string holes, specifically, I would recommend binder hole reinforcement stickers.

These are made of a tear-resistant material and you can add them to one or both sides of your holes to keep the string from cutting or tearing the paper.

You can also find them in a variety of colors and patterns, to spruce things up.


If you're using the rotary tool with a suitable engraving bit, you may find it easier to trace the state profiles by attaching the paper to the slate with an adhesive. Even a simple glue stick will wash off with water once the job is completed. By tracing around the shape, the lines you generate may be more consistently positioned by not being centered on the line.

Your question about handling the tool is going to be tougher to answer, as it is more dependent on your skill than on one practice being better than the other. With respect to the cutting bit used, unless it is designed to cut with the tip, the perpendicular placement may cause problems.

Another option you have would be to construct a caddy, a sort of "pen holder" to keep the tool at the best angle for engraving, providing a stable base while getting optimum cutting. A tool caddy will also enable you to accomplish a more consistent depth of cut.

If you have a maker space in your area, you may also consider to visit to see if they have a laser engraver available for use. I have a CO2 laser which will do a wonderfully accurate job of engraving slate, to nearly any reasonable depth (1-2 mm typical). You may find other members of the maker space equally helpful. I personally would be happy to take on this type of project for a fellow maker.

Directly related to the above, if you are unable to find a makerspace, consider to visit a laser related forum or two and cast about for a local laser user. If you are willing to pay shipping in both directions, your options increase. I use RDWorksLab occasionally, a forum aimed at users who own lasers with the Ruida controller line, but have since put most of my time in LightBurn, a forum for that particular piece of software. SE does not have direct communications between users, but you can find my username in either location if the shipping option works for you.


As a calligraphy beginner, what features should I look for in an ink?

All the liquid calligraphy inks I know of are ready to use, no dilution required.
Pigmented ink must be well mixed before use for the pigment to be uniformly dispersed.
I find acrylic ink sometimes hard to remove from the nibs if not immediately cleaned
Iron Gall ink flows well and is a pleasure to use but requires an acid free paper. The ink will look very clear at first but will darken when drying.
India Ink (what's called 'encre de chine' in French) is probably the easiest to find and to use. A good one size fits all.
Chinese calligraphy sometimes uses solid ink stock which is diluted in water on an ink stone. It's OK for brush painting but not easily usable in pens and nibs.
For pens the main factor is what can you put in them. If it's a cartridge system you're more or less limited to what is available in those. (I have seen refillable cartridges before, but they looked like a mess to fill.)


I live in a hard water area and always get limescale from my iron.  You can buy demineralised ironing water, but I tend to use the condensed water from my dehumidifier or melted frost from the very top of the freezer


What should I use to draw under oil paint?

If using graphite make sure to spray a few coats of fixative over the graphite drawing prior to painting.

  What should I use instead?

You could also try:

charcoal
Water color pencils
diluted ink


How can I describe this alien-looking sculpture art style / concept to find other examples?

Organic Kinetic Futurist Sculpture

Adding organic and kinetic gives many similar results like the sculptures of Patrice Pit Hubert


How can I protect my pencil & charcoal drawings once complete?

If the pieces are likely to be handled and/or displayed then using fixative sprays is probably the best option. There are two purposely manufactured types:

Workable
Final

Workable Fixative

As the name suggests, this allows you to add additional layers to your work after the spray has been used.

Workable Fixative is a thin solution and it sets up a new toothy (slightly rough) surface for more drawing. You can choose to spray the entire piece or isolated parts. To prevent other areas getting sprayed you can use paper, or frisket, to shield the areas that you don't want to spray. Once the fixative is dry you can continue working on the drawing.

The fact that it provides new tooth can be an advantage as heavily shaded/worked areas can become smooth making it harder to apply further layers of graphite/colour to the piece. So, you can use a workable fixative every few layers to keep a fresh tooth.

Final Fixative

This provides a more durable surface than a Workable Fixative, but this should only be applied once you are certain that you don't what to make any further adjustments.

However, a Final Fixative can cause the piece to darken so many artists do not apply the this layer and simply stop at a Workable Fixative.

Hairspray

Hair Spray has been mentioned as a cheaper alternative to fixative sprays. Below is a summarisation from Drawing for Dummies

  Hairspray does contain some of the materials of a Fixative but it only works for the short term, and ultimately damages the drawing - the hairspray yellows over time and ruins the drawing.

Do not use hairspray.

Applying Fixative

Use proper ventilation. Fixatives smells and is hazardous to your health.
Shake the can before spraying and test on a scrap piece of paper away from your drawing. The nozzle can clog & will deposit 'lumps' on your drawing
Directions on the generally say to spray 20-25cm (8-10 inches) from drawing. However, I spray 30-40cm (12-15 inches) from drawing. Make sure it is on a flat surface and not drafty.
Lightly spray first coat horizontally. Let dry for 15 minutes. Make sure the layer is even and smooth.
Lightly spray second coat vertically. Let dry for 15 minutes. Make sure the layer is even and smooth.
Subsequent layers may be added in alternating directions if needed.

The sprayed areas of your piece will become darker once you have sprayed it and it won't lighten once the fixative has dried.


Wish to paint dog in scenic background. What size should dog be?

I don't know any formal artistic composition rules but how I would handle it is by mocking it up with either Adobe Photoshop or Gimp Photo Editing Software.  (Gimp is free).  Put the background in one layer and the dog in another, then scale and move each until it looks good to you.

Then, just for fun... I apply an oil or watercolor filter to see what the finished product will look like.

Then I hire someone with talent because without a computer to do all the hard parts...  I suck at painting!


How to remove oven baked acrylic paint from glass used for drinking?

I would start with a razor blade and see if you can scrape it off.
If it doesn't readily scrape off, go to chemicals (below are suggestions that work with dried acrylic paint; try one at a time, do not mix them).  The procedure for all of these:

Cover the painted area with several layers of paper towel saturated in the chemical.
Wrap that with plastic wrap and rubber bands to seal it against the glass and minimize evaporation (don't leave any of the paper towel exposed).
Set it on a surface that won't be affected by the chemical you're using (avoid wooden or painted or finished surfaces; plastic or glass is a safer bet).
Use common sense and follow directions for personal safety (good ventilation, wear gloves and eye protection).
Let it soak under the paper towel for 30 minutes to an hour.  Then see if the paint has softened enough to wipe or scrape it off.
If it doesn't seem to be affected, try again with another chemical.  If it helped but there is still residual paint, repeat the process (try a different chemical if the result is unimpressive).

First chemicals to try (the least nasty; pick one):

Household ammonia (full strength)
Isopropyl alcohol, 91% - 99% (may need to shop around for a drug store that carries it at this strength)
Denatured alcohol (available in the paint section of your hardware store)
Goof Off (Pro Strength Remover or Paint Splatter Remover if varieties are available)

Second (nastier) group (outside is better; away from open flames or sources of sparks); most of these are available in the paint section of your hardware store:

Acetone
Lacquer thinner
Paint stripper (one containing methylene chloride and/or methyl ethyl ketone [MEK] is likely to work well)
Mineral spirits / paint thinner is something you may have on hand.  I don't know how well it will work, but if you don't have any of the other chemicals, give it a try.

Note that there are "green" versions of some of these products; many of them water-based.  I don't know which of those will work on dried acrylic or how well.
Some of these chemicals will evaporate pretty fast.  Even with plastic wrap, the paper towel may start to dry out in less than 30-60 minutes, so check it.
If you use any of these chemicals, clean the glass surface with alcohol and let it dry.  Then wash it with soapy water (running it through the dishwasher after the alcohol has dried is fine).


What are requirements for ballpoint/rollerball colour pens for art-grade drawing?

I can definitely recommend a fine asian gel pen (kind of rollerball). It is precise and very easy to use, unlike many other tools I've tried so far.
It's a perfect affordable tool for detailed drawings, like miniatures, doodling, pattern fillings, i.e. things that require precise,
fine strokes and points. Of course one can draw anything, but bigger areas will take some time to fill them out.
0.5 mm is the most common stroke width for handwriting.

For serious work a lot of ink is needed, so I personally use and recommend pens with standard-sized mass-produced refills.

Pens: for a start go for something like Muji or Muji clone:

This image above shows Muji clone - these are compatible with standard asian refills (13 cm). Original Muji are maybe better quality, but I am not sure about refills' compatibility--- I think original ones require some special sized original refills.
Note: I don't recommend or not recommend this brand, it is just an example for quicker understanding of choice aspects.

You can buy all such thing online e.g. on Aliexpress. Search for e.g. "gel pen refills". Beware that the quality may vary. Buying small amounts by different sellers is a good strategy to find good quality product.

There are 2 most common asian refill sizes, below is a photo for reference.

The longer one at the bottom (~13 cm) is the most common standard asian refill and it can have needle tip or bullet tip. Needle tipped pens can have finer stroke--- 0.38 mm, but that depends, you must test to see.

These 13 cm refills are always available by various sellers on Aliexpress, and can be found in different colors.

The shorter one (~11 cm) has a bigger volume, lasts longer, but I have seen them only with black/red/blue ink, 0.5-0.7 mm stroke.
Also I believe this type is more likely to be found in Europe & US shops.
It might have different design, e.g. come in a metal case:

Ink consistency & permanence

Higher price and known brands might be better in this regard, but anyway, always test it before buying big amounts.
Possible problems: bad ink consistency or ball defects. Too fluid ink is hard to work with especially for detailed drawings. This can result in daubs, uneven strokes, etc. Too viscous ink is also bad, because you will need to apply pressure to draw, and that is even worse
than too fluid ink--- pens with too fluid ink can be at least used to roughly fill big areas. Good test is to make dots on a paper - just gently touch and release the tip on the surface - fine, equally sized dots should appear.
Most inks are permanent, but if you want to preserve the drawing, protect it from water and mechanical damage.

Colors

Finding good colors is a real problem.
Usually there are 3 colors in mass production: black, blue, red. Green, violet, magenta are quite common too. Obviously black is the most demanded for drawing.
Other colors are more rare/expensive. On Aliexpress colored pens/refills are sold in bundles, normally without specifec color choice.
For specific colors--- better try contacting the seller and ask.
For my work, I had problems finding good natural colors, like specific shades of brown and green.

It is also feasable to inject ink into the tube with a syringe - there are many good color inks sold in bottles for fountain pens, but I am not sure how it will work out. Currently I am planning some experiments with tube refilling, so maybe I'll update this answer in a while.


What kind of lathe would I need if I want to turn pens?

There are several basic groups of wood turning lathes based on size.  There are the pen/mini lathes, the midi lathes and your full sized lathes.

Pen/mini lathes are the smallest. These are almost always bench top models have a small foot print and smaller swing often 8-10".  Bed lengths vary.

Midi Lathes are larger than mini's and tend to have a 10-12" swing, longer beds and most are bench top models, however some have stands.  They tend to be more powerful, since they can handle larger pieces than the mini's.

Full sized lathes are the largest, tend to be floor models (but not always) and have the largest swings, often starting about 14" and up into the 20's.

In reality you can turn a pen on any of them.  However, full sized lathes are overkill for size, power and price.  Midi's are reasonable to use especially if you turn things other than small items like pens.

This leaves the pen/mini's as the likely option.  They are the cheapest of the bunch, allowing more money for buying pen stock, the are the smallest, allowing for a small work space/shop, and they are designed for this type of work, which means it should have smaller error tolerances as well.

As pointed out in the comments, these lathes can also be used with resin stocks and other similar materials.


What is the best mix to make chalk paint at home?

You will need a good binder, and the cheapest waterproof binder that you can make yourself is casein.

Casein is a milk-based product that you can make by warming  whole milk in a saucepan and adding about 5 drops of lemon juice per liter. You don’t have to get it hot, but it mustn’t be cold. You will see clumps forming, and then remove it from the heat. Pour the entirety through a fine-meshed strainer and reserve the watery part (the whey). I like to let the casein dry for about 24hrs. Do not leave it in the sun, and do not accelerate the drying in the oven.

The next phase is to do what the Germans call “sumpfen”, and that means you soak the chalk for 24 hours in a clean bucket with distilled water before you mix it into the casein. While it is soaking, you can stir it several times to make sure that it is mixed thoroughly. It will settle to the bottom of the bucket. Don’t use too much water, because it isn’t necessary. Just use enough to cover the chalk.

The next day when it is time to paint and your surface is prepared (i.e. no grease spots, sanded down etc.) take one part casein to one part chalk and knead them together like bread. Once the consistency is uniform, put the casein-chalk in a paint pot and slowly add distilled water (even from the chalk bucket) until you get the consistency you want.

It is really a good idea to try out your technique and the paint on a piece of wood similar to the table. When the paint is dry, you can burnish it with a silk pillow, for example.

If you have extra casein, wrap it in plastic and keep it in a dark and cool place, like the fridge.


How should I select elastic for a sewing project?

This is commonly called the "stretch percentage" or "stretch factor". The name comes from how much percent of the original width/length the material can stretch. For example, if you can stretch a 4" piece of elastic to 6" long, the stretch percentage would be 50%.

Here's a simple visualization from Patterns for Pirates:

As a side note, some patterns come with a "stretch gauge", instead of telling you a stretch percentage. It's usually printed on the back of the envelope so you can easily measure your fabric against it:

What elastic to use really depends on your particular application! A thicker or wider elastic may be more sturdy but less comfortable, for instance. As a general rule, thicker elastics seem to be less stretchy - but it's a very general rule. If you know the measurements you want for the finished pants, you can come up with the required stretch percentage: (fabric width / fitted width - 1) and bring that gauge to the store to find which ones are suitably stretchy.


Repairing a detached cover on an old leather-bound, sewn book with marbled end papers

Definitely don't attempt to repair it yourself - I can't tell for sure from the photo, but I think this is a hollow back binding. In this style of binding the covers and the spine were build directly on the book block, not glued together separately and "hung" into the covers as is done with modern hardcovers. That makes fixing a (partially) detached cover harder.

In a modern hardcover, you would fix this approximately by:

detaching the end paper from the book block on the broken side,
lifting about an inch of the end paper from the coverboard,
pasting a strip of cloth or thicker japanese paper over the torn cover joint,
pasting a strip of thinner japanese paper over the torn end paper joint ,
reattaching the end paper to the cover board and the book block,
and optionally, painting the new material paper to match the surrounding if it's showing through.

Better hardbound books will have the book block attached to the covers not only by the end papers but also by paper,cloth, the ends of the tape/ropes the book block was bound on, etc. These can stay attached, since you can paste the patch over/around them.

In a hollow back... I'm not sure, to be honest. I never actually made one, although I know the approximate steps, and I definitely never tried to repair one.

The main catch is that since the spine is constructed directly on the block, you can't just detach the end paper to get access to the joint. My best guess is that you would still detach the end paper from the book block; then you might need to cut a slit between the book block and the spine hollow to insert the patch. In best case scenario you would want to avoid opening the hollow, but rather insert the patch between the layers of the back "board" (it's not actually a board, it's several layers of paper pasted together).

If you plan to get this book repaired, definitely check the credentials of the professional. Check their portfolio if they have it, ask directly if they ever worked with this type of book. Hollow back binding is very common on older books, so you should find someone easily, but I assume it would be also easy to be a "professional bookbinder with book repair experience" without ever getting your hands on one. If you don't want to alienate the person, be the curious book owner and ask what kind of binding this is - the right kind of bookbinder will tell you a lot more than I could ;)

Also, if this is the only damage the book has and you don't use the book often... maybe the safest thing would be to leave it be. It doesn't look like a big tear. Store it in dark, dry place, avoid non-archival materials and pests, and it will be alright for a few more decades.


Q1: I'd suggest sewing a layer of black nylon between. Black will block any light trying to shine through the flag, and only allow light to be on the flag.

Q2: Does the nylon need to be bonded before cutting? If the nylon is being heat-bonded to the flag (I'm assuming this is the same project), I would do a test run with some scraps:

wood board
aluminum foil
fabric (face-side down)
bonding material (interfacing?)
a layer of wax paper and/or another of aluminum foil
top it off with a wet rag

and iron that fabric sandwich.

The wood will keep everything still and help prevent slips or stretches
The wood and foil should help keep the heat localized
The layer above the adhesive should be something easily removable, like pulling a sticker off it's original waxy paper
If using another layer of foil, it'll again just help direct that heat to whatever is under the foil
The wet cloth is important, and perhaps keep some extra water handy -- heated water will not go above 212F, so as long as the cloth is wet, that's going to be the highest temperature you should be able to use. Most interfacing should melt at this temperature.

If you're bonding nylon to nylon, just make sure that wherever you have exposed heat-bonding stuff you keep it covered with wax paper or something like that.

Oh, and if you're avoiding sewing altogether, just use the same heat-bonding stuff around the edges of the inside part of the overall flag. You could take the black nylon, cut it to the same shape as the other two faces of the flag, then heat-bond one face to the liner at the edges, then do a second round of heat-bonding (I'd suggest two separate ironings for this, you wouldn't want one face to only partially bond because it didn't get enough heat for the glue to melt)

HTH