A quick search for "tape measure spring" resulted in a list of various products, but also included the term "recoil spring." Changing the search term to "recoil spring" really threw a wrench in the works, however, as some of the returns presented items related to gun-type weapons.

More appropriate to the question is that recoil spring also appears when dealing with pull-start engine mechanisms. As with a tape measure, extending the spring loaded portion (starter rope, tape measure, etc.) causes the recoil spring to tighten up, providing the retraction force in the expected and desired manner.


What colour is a mix of two perfectly proportioned complementary colours?

As the answers in your other question (Why do complementary colours desaturate each other?) and the link in the comment by Danielillo address, it will in theory be a perfect grey: the complementary colours will have complementary temperature and value, so, after mixing, any pair of complementary colours will have the same perfectly neutral grey.

Of course, concerning the 'analogue' arts, in practice, other factors weigh in, like the quality and opacity of the pigment, and its coarseness. This will make the mixing harder, the proportions variable, and in most cases causes an overtone of the stronger colour.


Is there such thing as squeezing your values?

As a non-native English speaker I'm not too familiar with the expression 'pushing values', but I think the intent goes both ways, that is to say, it doesn't mean pushing them in one direction, but in both (or all) directions.
Pushing one's values too far either results in a high-contrast image, where all values have been replaced by binary values (resulting in a kind of poster decal art style), or is simply not really possible (within the use of this expression as a technical criticism), since values can only be stretched to a certain limit and can therefor not go too far.
It seems to me this is a matter of semantics, more than it is of art theory.
'Squeezing one's values', or rather 'limiting one's values', has a somewhat opposite meaning, and is illustrated well by the left part of the painting in the picture of the accepted answer in the question you linked (here).
Limiting the tonal range makes the image look hazy indeed, as the contrast has been limited, and this is exactly what happens when looking at objects through fog, or mist, or smoke, or from a larger distance (see also atmospheric/aerial perspective), or in the twilight, where the additional effect of diminishing colours can be appreciated even more clearly.
This expression ('squeezing values') deviates slightly from being an exact opposite of the former expression ('pushing values'), in the sense that these values can be 'squeezed' or limited within several value ranges (it is not a binary adaptation), e.g. the edited images on the left and right of the centered original below:

Euan Uglow | Two Apples (source). Here the Curves tool in Photoshop was used to limit the colour range
As you can see, the difference in atmosphere in both edited images is dramatic: the first seems to want to convey a certain gloominess; the second gives the impression the artist wanted to show the intense and warm lighting of a summer's day. (Whereas the original exemplifies Uglow's generally quite neutral palette - although any image naturally would have its most neutral-looking version in between these renditions.)
Limiting your values like that will usually let lighting play a more important role, but everything will depend on the (intensity of the) colours one chooses: colours can become desaturated when changing their value, but you can also opt to only work with colours within a certain value range to best maintain their saturation.
To get an idea of what can be achieved with limited value ranges, I suggest looking at the works of Giorgio Morandi specifically, and several symbolist painters (like Pierre Puvis de Chavannes), some (renaissance) frescoes (esp. Pierro della Fransesca), and maybe Vilhelm Hammershoi for his twilit atmosphere.
Unfortunately, I can't yet think of a good example of an artist working with predominantly dark value ranges.


Polystyrene sheets (thermocol is one brand) and cardboard sheets are your friends here! Take the polystyrene sheet, cut it one inch longer than the drafting film on all sides, cover the poly-sheet with colored paper or paint it (optional, and not really necessary as yours is oil painting, but would be needed if it's just a pencil or charcoal sketch), stick the film on the poly-sheet (don't use hot glue or superglue on polystyrene ever; I learned this the hard way), then turn the painting upside down, with the painting facing the floor poly-sheet on top, and stick a cardboard sheet cut exact to size and then long strips of cardboard for the sides and the extra inch you left earlier on the top.

Pros: Looks like a legit frame because of the brown color of cardboard, is much lighter, is very cheap and easy to get your hands on

Cons: Absolutely none

P.S. For the glass thing you were talking, you surely can put glass on it but that would make it sensitive and fragile, so maybe you can also try saran wrap or maybe OHP sheets. With glass you always have to be super conscious while handling it, and also while picking up from the sides so you don't cut yourself; this way it's just more kid/teen/student friendly. But if you're an adult and it's going to stay in your office or on a private showcase, etc, go ahead, use all the glass you want.


What can I use to make grips for my felting needles?

Have you considered sugru?

A silicone-based rubber for lots of "hacks", adding ergonomic grips or softening handles being one of them.

(Image source: manufacturer's website)

The material can be removed from all non-porous surfaces, so your single needles won't be harmed.


What are these balls of wool bound together with a rubber band?

These are just pom poms on elastic  bands. Those particular ones appear to be made from rabbit fur. That is, according to the less that useful description given from the site where this image came from.

  Korea cute fashion real rabbit fur ball hair ring hair rope single ball wholesale

 Page appears to be in Chinese Simplified and that is what I got from Google Translate

The ones pictured are used as decoration or as an accessory.

Coincidentally we had another user ask about how to make those recently. Have a look at the answers to this question and you should get an idea of what to do. The only thing that is different is the presence of the elastic band. If you do want that it would just be a matter of attaching that into the pom pom as it is being created.


How can I attach casters to a 1/4" plywood board when I only have access to one side?

A butterfly anchor (also called a toggle bolt) allows you to drill into the plywood and insert the toggle from the accessible side. Then tighten and the bolt will hold very tight. Enjoy!


How do I blend charcoal enough to make it look like a skin surface?

You will probably need medium and soft charcoal for creating smoothly blended surfaces (like her skin), and some hard charcoals or perhaps even a carbon pencil (which contains a mixture of charcoal and graphite) for the crisp textures of her armor and the fine lines of her hair.
For blending, you may want to use a tortillion or a blending stump and a kneaded eraser.

Source: https://rapidfireart.com/ <-- also has many great tutorials on how to shade
Tortillons and blending stumps are tightly rolled pieces of paper with a tapered tip. You can either buy them from an art store or make one yourself. They can be used with both pencil and charcoal, and they're better for blending than using your fingers, since your skin contains moisture and oils, which can cause the charcoal to clump to smear unevenly.
Here is a thorough response describing how you can use a blending stump or tortillon for blending: How do I get a blur effect in pencil drawings?

Source: https://thevirtualinstructor.com/blog/10-essential-drawing-materials-and-tools-for-beginners
A kneaded eraser is a soft, stretchy, gummy material that can be used for lifting, removing, and blending charcoal or pencil. Aside from removing "mistakes," erasers are also great for blending. This video does a nice job of demonstrating some different techniques for using kneaded erasers with charcoal:
https://www.youtube.com/watch?v=PIAKBVfl_YU

Source: https://phoenixartsupplies.com/art-supplies/strathmore-500-series-charcoal-sheets/
As for paper - there are many different types of paper out there for use with charcoal. You can usually find charcoal paper pads at art stores. You could draw on white paper, like the original pencil drawing. But if you have white charcoals (for drawing highlights), you could use toned paper. This can help make your subject "pop" off the page. For sketching and practicing, newsprint paper is a great (cheaper) alternative.
Here are some good resources for learning about types of charcoal paper and their characteristics:

https://nitramcharcoal.com/selecting-perfect-paper-charcoal-drawing/
https://www.artistsnetwork.com/art-mediums/drawing/best-paper-for-charcoal-drawing/

Hopefully this helps! Feel free to ask any questions. I'm not a professional artist, but I've had some experience with charcoals and pastels. If anyone else has additional tips, feel free to comment below.


You could use acrylic paint or a carbon fiber vinyl. Not sure on how well the acrylic paint would work, but both myself and my fiance has used the carbon fiber


Why not start with a copper chain and see how much fun it is before the expense of platinum ? Copper wire is readily available in giant size range. Platinum wire sizes will be limited. They seem to be in about the same strength range depending on the amount of cold work. When our technicians wound custom heating equipment with platinum wire , there was no problem working it, no special handling (other than to lock up the spool of wire when finished). . I expect you will want annealed wire . If you need to soften it after working it needs only about 1400 F which you can get with a gas stove or propane torch.


Is there anything wrong with mixing incompatible paints?

So, from my experience...

Wrong? No. Basically, looking at the major art paint options I can't see any that, when combined, would result in a dangerous mix. Some, however, will mix a bit better together than others.
Yes and no. The key to the cracking effect is difference in drying times, some paints dry faster than others and when you apply a fast drying paint over a slower one, the result can be that the upper layer will crack. The "no" part of this comes from the ability of some mediums to adhere better or worse to each other. For example, acrylics use water and oils, well, oil. When you try to apply acrylics over oils, it will crack and split (your desired effect), but it will also tend to flake, which is less desirable. In any event, some mixes will probably work better than others, but there's likely to be some trial and error involved.

So, my suggestion is that if you're going to give a go, do so on some items you don't care about, but that also has the same surface material and try a few combinations using some student-grade paints (much cheaper).


How to interpret this gauge requirement?

Usually, the gauge is given in both stitches and rows, for example
"Gauge: 10 sts/15 rows = 4 inches in stockinette (regular knit) stitch."

You rightfully care about gauge - and typically should always check it - to insure that your final product will have the correct dimensions.

The three elements of how to adjust your gauge are:
(1) needle size
(2) yarn weight, and
(3) tension.

You can adust any of the above to get the correct gauge.  Usually, the variable you will modify is needle size, since how you knit is just how you knit (the tension of your knitting is characteristic of how you knit).

The weight of the yarn is not usually something you want to change since you have carefully picked out your yarn in advance (and are making your gauge swatch from it!).

Since your pattern does not stipulate the number of rows in the gauge, I recommend just checking the number of stitches in the row - the horizontal dimension, and adust to obtain the correct width. (note: As one commentator suggested, a scarf is one instance where the length may not matter as much as it would with a structured item like a sweater.)

Here is a more detailed, but simple, explanation and a good reference for checking gauge: follow:http://sheepandstitch.com/what-is-knitting-gauge/

Good luck and happy knitting!


I'd recommend checking out YouTube, there a bunch of methods and they give you a full tutorial on how to do it. I tend to cut so there's may a centimetre of two to fold back thread with a needle and pull tight, a bit like this tutorial but only up to step 4. You can go on to cover the back, but it's all mostly down to your personal preference.


Porcelain brush pen does not stick to ceramic ring

From the "usage" section of the pen website (my emphasis):

  Daily cleaning: avoid friction, rubbing and scrubbing by positioning the item in the dishwasher so that it is not in contact with other items of crockery or cutlery

These pens are listed as decorative. You are not going to get a permanent bond that is as strong as the original ceramic finish. I am sure if you were to paint and fire the decorations, and then set them on display where they cannot be rubbed or scraped against things, the paint will hold up fine.

If you wanted to get a permanent finish as durable as the original material you would have to reglaze the item using porcelain glaze and a kiln capable of extremely high temperatures, between 2381℉ and 2455℉ (1305℃ and 1346℃).

(source)


What kind of triangle / ruler is shown in this video?

It’s a ‘Brown + Sharpe toolmakers knife-edge #530’

In the video he was probably just referring to the second ruler he showed with the bevelled edge.


How to open a hot furnace without damaging it?

There are ovens made to be opened when hot and there are ovens not made to be opened when hot.
From what you mention what the manual says, yours can not be opened when hot.
As there are different parts that go wrong at strong heat loss or getting the full blast of the oven heat, it is impossible to predict what your oven can handle and whether you can adjust it.
Your best bet is to replace this oven with one made to be opened when hot. Your second best bet is to ask the maker or a community of oven users where someone may have more knowledge.


Print drawing on water color paper, is it possible?

Laser printer toner is water resistant -- more so than most paper.  But the toner doesn't necessarily stick very well to papers other than office paper and specially coated materials. Toner can also look rather shiny.  So this could be a good option for your tests of different effects, but less so for the mixed digital/watercolour pieces.

Inkjets have the advantage of using ink which will look much more like the ink you'd expect especially on watercolour paper.  Some are water resistant, some aren't. I've got an epson that's over 10 years old now; the ink for that doesn't run on normal paper (though it does a little on photo paper).  There's a very slight solvent smell as the print comes out.  Printers I've used in the past have varied.

You'll have to test on any printer you have in mind.  I suggest that you test on office paper using only the inks you want to use for your project -- probably just black, which would be a good thing as there should be fewer components to run (be sure to print using "black ink only" or a similar option; some printers use black and the coloured inks to produce black. You'll have to further test the printing on your watercolour paper, trying different paper options in the printer software.

If you're looking to buy a printer to do this, at least try to get a demo print on office paper and see what happens when you wet it.  The availability of T-shirt print transfers might be a minor guide as T shirts have to be washed, but the transfers might bond the ink to some extent.


How can I extend the life of clear nail polish?

Some people use acetone to thin down their nail polish to its original consistency, but this is not recommended since it will cause it to dry out more quickly after application and can cause cracking in the finished result.

There are a number of products available on the market; they are intended for extending the life of normal nail polish but I'm not aware of any reason they wouldn't work for clear nail polish also.

You need to search for 'nail polish thinner'

Also, be aware that shaking the bottle or pumping the brush in and out will cause it to thicken more quickly.  Ideally you should roll it between your palms before use instead.


Alternatives to Citadel / Games Workshop Paints

Citadel paints are essentially just acrylic paints. If you're not sure you want to make the investment yet, you can use any standard craft-grade acrylic paint while you practice; I'd recommend investing in a flow medium to help prevent obscuring the small details in your miniatures, and not starting with any valued ones. (Dollar store plastic army men are a great way to practice.)

The advantage of Citadel and other paints formulated for miniatures is that they're designed to use on very small, very detailed objects. Basic craft acrylics tend to be designed for use over larger areas on larger objects, and thus tend to be thicker with a coarser pigmentation. Miniature paints use an acrylic medium with a greater flow, and pigments and mica (metallic pigments) with a finer grind, to enhance their appearance on miniatures. This difference in formulation contributes to the difference in price between the small pots of miniature paint and large bottles of craft paint.


How do you accurately mark fabric without a pattern?

There is always the option of making a pattern - i.e. an appropriately sized piece of paper. Then you can use it as you are accustomed to.
For rectangular patterns, remember that when you fold an edge onto itself, the resulting crease line will be perpendicular to the edge. This helps a lot when constructing a rectangle.
So if your fabric is sturdy and not prone to distort, arm yourself with an iron and start ironing, folding, and ironing, etc., always measuring your distances. If however your fabric won’t necessarily hold its shape, I recommend the homemade paper pattern route.


Can I substitute fusible interfacing for sew-in interfacing?

Now that I've seen the pattern, I would say that for the handles to stand up by themselves, as shown in the pattern,

and for the bag not to flop over, as they are wont to do, hair canvas would be much more effective than normal interfacing (whether sewn in or fusible).  I've seen hair canvas used in tailored jackets (not the modern "deconstructed" kind) to give body to the shoulders, collar and lapels.

Here's how Pellon describes it:

  Sew-in Hair Canvas Interfacing is an excellent tailoring product. It is a woven interfacing that is suitable for garment construction where crisp detail or firm control is desired. Use with medium to heavyweight fabric.

When I was googling hair canvas I came across a fusible kind which, if Pellon is selling it, should work similarly to the sew-in kind.

If the shop where you live doesn't sell hair canvas, you could ask them what they can recommend as a substitute, showing them the sketch and photograph of the bag.  Basically, you need something appropriate for creating a crisp, tailored look.

I recommend making a full lining even if the pattern doesn't call for that.  It's much nicer to rummage for some small object that's floating in the bottom of the bag if there's a nice, full, smooth lining.

I take back what I said about fusing to the lining.  For this kind of bag the lining should be soft and flexible.

By the way, I believe fusible interfacing can in principle be sewn in.


Paper's preservation (fixative not working)

Paper will yellow over time because of lignin in the pulped wood.
Choosing an archival, acid-free fixative means that the fixative itself should not yellow over time. Unfortunately, the primary purpose of the fixative is to prevent smudging of the media that is on your paper. While it can slow down paper yellowing over time (by reducing the surface area of the paper that is exposed to air), it doesn't neutralize those oxidizing chemicals.
There are ways to treat the paper to prevent the yellowing from getting worse, and you can also put it behind UV-blocking glass to protect it from further oxidization due to air and light. However, the current yellowing may not be reversible.


What are the benefits of using an overhand grip?

The tripod grips are used mostly for drawing "lines", whether plain writing of text, or drawing contours.
However, the overhand grip is used mostly for filling areas, e.g. backgrounds. This grip keeps the tip away from the drawing surface, allowing the side of the pencil (or drawing tool in general) to contact the paper. The result is a more uniform spread of the "color".

Which joint should I mostly be using with an overhand grip? (wrist / elbow / shoulder / a combination).

It depends on the several factors, e.g.:

your position on the chair;
the size and shape of the drawing area;
the specifics of the "pencil";
what is comfortable for you;
what result you want to get; moving different joints results in different spread of the "color";
others.

Is this grip practical for painting? (or is it exclusive to dry medium)

It depends on the brush. If you use normal brush and any tripod grip, applying slightly more pressure results in the hairs bending and getting a result similar to the overhand grip.

Are there other benefits to using an overhand grip, apart from large flowing strokes?

Painting related: A special situation is when you need to add color inside a large, still wet area. In that case you will probably rest the wrist somewhere outside the painting, and use an overhand grip to apply the color to the desired area. If you need to draw a line in this situation, then it is quite likely that you will need to use a very thin brush, maybe even one with a bent "neck".


What is considered the most durable concrete for jewelry?

Mainly a terminology thing, but "concrete" wouldn't be used for jewelry.  That term refers to a mix that includes large aggregate that's held together with a cement binder.  On something like a road or sidewalk, the layer of rocks provides the strength and the cement just holds it in place.  On relatively thick art castings, you might be able to use a filler of aggregate the size of say pea gravel or aquarium gravel if you need compressive strength.  On small items, especially jewelry size, there would be no need for aggregate, and its presence could even work against you.  If you wanted the appearance of the aggregate, you might need to make an over sized lump containing aggregate and then cut it to size with something like a diamond blade.
At the size of things like cement countertops, large bowls, and art sculptures on buildings, what's used is typically a mix of sand and cement, sometimes with strengtheners like embedded fibers.  At jewelry size, it's typically sand and cement.  The particle size used depends on the item size and surface texture/detail desired.  For example, if you're casting tiny beads or something that will have a smooth surface with fine detail, you would need a very fine particle size.
If your objective is something that looks like concrete, with a grainy surface texture, you can use products sold as concrete toppers (the particular product selected wouldn't make much difference for your purpose).  These are designed to add a thin layer on top of existing concrete as a repair or leveler.  They are generally very strong because a thin layer has to hold up to wear and tear.
If your objective is something that looks more like polished stone, with a very smooth surface and/or fine detail, there are a few products designed for that purpose.  One is cement mixtures designed for countertops.  Another is a product that's popular among hobbyists for small castings, made by Rapid Set, called Cement All.
  Image courtesy Home Depot
It's available at hardware stores, and package sizes include relatively small quantities that will go a long way if you're just using it for jewelry.  You can mix it to a soupy consistency and make extremely detailed castings (if the mold is very smooth, the result will look polished and shiny, like polished stone).
The filler is very fine silica, and the binder is CSA cement rather than Portland cement.  CSA cement is superior to Portland cement in that it is stronger, doesn't shrink, reaches full strength faster, etc.
You don't need to add anything to these cement mixes for strength, they will be plenty strong for jewelry purposes.  There are dyes you can add for a desired color.  Concrete is porous and can absorb stains if it's handled a lot.  You can seal the surface with a sealant designed for countertops, coat it with resin, or just spray it with a clear finish.  Cement can be brittle, so dropping it on a hard surface could chip or crack it.  Coating it with resin or a clear finish would provide additional protection against that.


What is the term for drawing wireframes which are drawn before drawing the actual object?

Those are your construction lines.

Be advised that this term is also used for 3D modeling, and you may need to filter CAD out of any web searches.

They can also be called guidelines.

When drawing figures, they're often called mannequins.

These terms can be a bit generic. What will help find tutorials or guides is a combination of construction drawing + your art type, such as figure or still life.

You may find success looking at contour lines, as another answer suggests, but contour lines typically have a different connotation in drawing. Contours describe the visible surface and outlines. They don't describe the wireframe/unseen surfaces as seen in the tutorial you mentioned. Just be wary in looking for contour drawings, as that will lead you to a different type of exercise/drawing technique.


Can I be a painter as a colorblind person?

You can be a painter, but you should expect to encounter more obstacles and limitations than a person with normal color vision.

Have a look at the color wheel:
Color wheel

If two opposite colors look so similar to you that you would confuse them, you're going to have problems.

You may not be able to paint some red or green objects in a realistic way. If you paint a red apple in a way that the painting looks like a perfect copy to you, it may look different for a person with normal color vision.
Red and green behave totally different if mixed with different colors. That might actually help you identify the paint on your pallet, but it may cause problems and accidents as well.
Red is a "warm" color, green is a "cold" color. Using the wrong color might totally destroy the mood of a painting, but you could use this as a contrast as well.

You'll have to learn to paint like anyone else, but you'll also have to learn to cope with the fact that you see colors in a different way. This doesn't mean that you cannot become an artist. You have to find your own style like anyone else, but some art styles might be impossible for you to be good at.

You could buy an inexpensive set of colors and experiment with different motives. Read and learn about color theory and show your works to friends and family. I doubt you'll get it completely wrong.


How I can calculate the hand position on a clock background?

If you have a compass, the drawing kind, not the magnetic kind, you can create the intermediate locations for the hours.
https://youtu.be/2Vshz0kqZh4
The video above shows the process, but I was skeptical until I realized that it's a collection of overlapping equilateral triangles. Equilateral triangles have 60° in each vertex. You want to segment the 90° of the currently created locations (12, 3, 6, 9) into three pieces, 30° each. 90° - 60° = 30°
If you create an equilateral triangle with the base on the 3:00 line, for example, the 60° line of the triangle becomes the 1:00 position. If the triangle is created with the base on the 12:00 line, the triangle provides the 2:00 position.


Consider a clear-drying epoxy. Note that not all epoxies are equal. In a general sense they can bond different materials together with ease.

Here is an earlier epoxy advertisement where they glued a car to a billboard with an epoxy resin.

  1983 a visual stunt presentation was set up to show the strength of Araldite by gluing a yellow Ford Cortina to a billboard on Cromwell Road, London, with the tagline "It also sticks handles to teapots".

You can usually get 2 part epoxies in a dual syringe form and they are very economical. Depending how often you do this you might want to try a smaller one first as the shelf life of the product varies once used.

  Cheap and quick curing options would be great but I understand you can't have the best of them all.

Only part about this that does not meet your requirements is that they have a longer curing time then something like a craft glue. Setting inside an hour but fully curing over several days is needed in some cases.

The resin and hardener are kept separately as liquids, hence the dual syringe. In larger applications they would be two separate containers. I would suggest not applying directly to your project from the syringe but onto a disposable piece of cardboard or similar. That way you can manually mix the liquids together (usually 1:1 ratio) to ensure an effective reaction. Then use an applicator (craft sticks) to apply to the project.

You are going to want to clamp this down with decent pressure. There would be the issue of seepage while setting you need to be aware of. Depending on how intricate your cuts are the solution will come out of the wood acrylic sandwich. You want to try and wipe that off before  it sets. Epoxy resins dry really hard so if you have to cut part of it off it will no longer show clear on the cut. You can polish the edges once it cures with extra fine sand paper and / or a polishing compound.

A long term issue is that set epoxies can yellow over time because of UV radiation. That is likely a moot point as you are making a key chain.


How do I stop my finished pencil picture from smudging?

Fixative spray will prevent most smudging. Use a permanent fixative for a finished work that you don't intend to rework at all. For an unfinished work, you can prevent smudging earlier layers by using a workable fixative. Always test on a small area first.
Hairspray is an easy, cheaper fixative alternative. This option is good for students and hobbyists, but is not archival quality and may affect an artwork negatively over time.
Archival art/photo sleeves are good for preventing smudging as a result of rubbing against other artwork in storage or during handling. They are flat, clear bags that come in many sizes and have a resealable flap to keep artwork from sliding out.
Framing artwork behind glass will protect it from smudging even if you do not use any kind of fixative.


How can I make my old acrylic paints dissolve and flow freely again?

I suspect that you are encountering a problem with the clumping of additives or fillers, because in a closed tube it is rather impossible to have acrylic dry. You could try to regrind them with a heavy glass pigment grinder, which would probably help to disperse the clumps. Instead of water also try adding a bit of acrylic medium or binder.


Type of adhesive to use to attach seashells to a frame already glued to a wall

There are two challenges to your project as I understand it...

The frame (and maybe even the shells) has a nice smooth finish which glues don't adhere to well.
The frame is mounted on a wall, making clamping difficult.

Abrading the backs of the shells with a wire brush may roughen them up, allowing glue to hold onto them better.  Drilling small holes through the frame finish in spots which will be covered by shells would serve the same purpose for the frames.

As for clamping, use painter's tape.  After you glued a shell where you want it
on the vertical frame surface, secure it with tape to give the glue time to dry.  The tape may not be able to supply much pressure to the drying joint, but immobility alone can help form a strong bond.

With those challenges behind you, the choice of glues is based solely on the materials involved.  I've always had luck with gorilla glue which comes in a gel version for flow-challenging uses.


You need to create the initial surface coat that can both smooth the rough surface of the Styrofoam and create a surface for further material adhesion. There are actually a number of safe and simple approaches that you can do which all have a similar outcome. First though you need to be aware of what you should not do.

Be wary of products that will dissolve styrofoam

There are a number of products that react to Styrofoam on a chemical level and cause it to melt. Many spray paints can do this as well and products that contain paint thinner. Many product labels will mention what materials they are and are not designed for. If you are not sure sticking with one of the suggestion below would be advised or at least test in a controlled and well ventilated environment if you must.

Initial coating options

It does not need to be any sort of heavy coating but something that will try and provide a more uniform surface. In no particular order:

Mod Podge / decoupage: Mod podge will work on its own with one or two layers built up. Some light sanding in between layers will help create a smoother surface. You don't need to use the glue alone. You can decoupage as well.
Paper mache: Using the foam as a base paper mache onto it. I would likely do the entire object (all sides) as this might not adhere to the foam well or at least not long term. Doing all sides would give it no where to go. Not my first choice but this is a fun option for kids.
Styrofoam safe paints: I don't have any specific suggestion here. You will have a hard time using a brush given the rough surface. You might need to use a cloth or something similar to work the paint into all the holes. Let it dry and repeat the process. It will get easier each time as it gets smoother. Water and Acrylic paints apparently work just fine here.
Plaster of Paris / Geeso / Drywall compound: These should be easy to apply to the surface. Don't put it on too think. Much like other approaches Let dry and sand. Drywall compound would be the last choice of these options as it would be brittle. Should still work though. I am putting Geeso in this list as I think it works almost the same although I have no experience with it.
Commercial Options: There is a specific product called Foam Finish which is marketed for use with Styrofoam and related foam products. Likely there are similar products under different names.  Consulting a hobby store will help you get the variants. From the container you can see it would work well in this situation and you can read more at one supplier's site. :

  Repairs dents & nicks in all foam including Depron EPP, EPO, Styrofoam & more.
  Helps make foam stronger with virtually no extra weight.
  Creates a smooth surface for decals or paint.

In almost all cases the key is to keep your initial coats thin and build up to strength and uniformity you desire.

All of these should get you a good working surface that you can paint whatever you want. You should be able to glue object as well to the new surface of your foam.


Oil paintings can be damaged by salt air and humidity. Other concerns are exposure to natural light, and sharp changes in temperature that can cause the paint to expand and contract and potentially crack or chip.

Rare and valuable paintings are kept under controlled temperature and humidity conditions and protected from natural UV light.

Two things that you can do to protect your painting are to keep it out of direct sunlight, and frame it with glass.  There are two things to take into account if you protect your painting with glass, (1) the paint must be completely dry, and (2) the pane of glass should not touch the painting.

Please see a similar Stack question with mention of glass placement over an oil painting: Will putting an oil painting under glass cause damage?


What kind of glue should I use to create a perfect bound paperback?

There are machines for doing perfect binding on a small scale.  They start in roughly the $50-$100 price range, and go up from there.  They're generally "thermal" (they heat a strip of hot melt glue in the binding).  If you search "thermal binder", you'll find a bunch of options.  Here's a random, low-cost example from Amazon just as an illustration:

Source

Most of the large companies that make binding equipment and supplies, like Fellowes and GBC, offer versions.

The general way they work is you use a cover that has a glue strip in it.  You wrap the cover around the pages and stick the assembly in an upright guide over a heating element.  The machine melts the adhesive, then you stick the book in a cooling stand.  The whole process takes a few minutes per book.

You can buy premade covers that have an opaque back and transparent front, so your own cover art shows through.  They also sell glue strips that you can stick in your own cover.

I've used similar machines that were more "commercial grade".  The process is simple, fast, and clean, and the results look very professional.  They work with any type of paper and don't affect the printing (the heat is applied only to the edge).

If you mess up, or need to remove or replace a page, you can usually just put the book back in the machine, remelt the glue, and swap out the page.


Can I make doublets with a Genie and a trim saw?

It seems that, according to their website, your Diamond Pacific Genie is able to flatten and polish gemstones using the "right hand wheel" as a platform for, e.g.,

"Lapcraft "No Hole" discs [like this one]. They screw into the right hand wheel adaptor of the Genie, giving you a 6" diameter lap with no bothersome center hole."

You could also look into exchanging your trim saw blade with a polishing stone, something that is probably dependent on the model and type of connection.
Not to mention that it can be dangerous, as trim saws have different speeds and were designed for different pressure types and lighter attachments.
Try at your own peril :)

There is also a multitude of tutorials on homemade flat lap machines available online.

Although I have no experience with gemstone crafts, and contrary to rebusB's answer, I suspect two not completely flat surfaces will bond perfectly fine and invisibly when using the right bonding: a slow-curing epoxy might work, or G-S Hypo Cement, with which - provided they can be made fluid enough to fill even the smallest visible imperfections - you will be able to join the compounds without a clear visual boundary. As long as the bonding is clear and as thin as possible, I don't think this will be very obvious. You can heat up the glue a little to get rid of air bubbles, as mentioned here.
It's hard to find anything to back up this claim, though, so I suggest trying it out with inexpensive materials (some pieces of glass, perhaps, as this will make any imperfection readily visible).

Lastly, as a friendly reminder: be sure to wear respirator masks when polishing. You don't want metal fume fever, silicosis, or similar illnesses.


The term for someone pointing at an object to attract attention to the object

In painting, this figure is called a festaiuolo:

[Artists of late medieval and Renaissance Europe] relied on festiauolo - figures who attract our attention by glance or gesture, point us in the appropriate direction, and indicate how we should respond or behave. The concept of the festaiuolo was taken by artists from the Italian theatrical and celebratory conventions. On stage, he or she was usually a secondary character who served as an intermediary between the audience and the main action, explaining, commenting, and modeling the appropriate response. The meaning of the word itself, literally "feast-maker", suggests the role of master or mistress of ceremonies, who would perform introductions and direct guests, and so the festaiuolo functioned in a work of art.
Scholarship and Christian faith: Enlarging the Conversation; Douglas Jacobsen, Rhonda Hustedt Jacobsen; 2004. p. 144

This pointing can be to something or someone inside the painting, as well as outside of it, in which case it usually is a concept, like God or Fate (here is a related thread on History.SE).


I don't see any reason why a cork tree couldn't be created using other materials.  Wooden dowels, cut in one inch sections could be hot melt glued together for a similar effect.  The same could be done with cross sections cut from small tree branches.

On a larger scale, you could assemble a similar tree from empty aluminum cans or water bottles.  In both of those cases, you would want to align the containers upside down relative to the front of the artwork so that decorations can be added to their comparatively featureless bottom sides.

Theoretically, you could scale this up to paint cans, barrels or any grouping of cylindrical objects.


Differences between silver jewelry alloys

Stainless steel ( assuming 316 ) is more corrosion resistant than silver and would not darken in air. Silver darkens with exposure to hydrogen sulfide ; yes I know there is "no" H2S around the home. However some smell from eggs is a ppb ( part per billion = not very much)  of H2S , and most of that and sewer gas H2S finds and reacts with any silver turning it dark. Most have experienced putting silver in a drawer or box and finding years later that it has darkened ( from sulfide). 92.5  % is the minimum silver content to be called sterling silver, so presumably both items are silver, the balance is primarily copper,  but may have a little nickel or zinc. My guess is that the brighter piece has a plating like rhodium to prevent the usual darkening of silver. But the real answer is that a jeweler would need to examine it.


Disclaimer: I've not tried this, so I can't guarantee it will work.

One thing that I've seen suggested is to soak the leather with water and then heat it - this should cause the fibres to swell and reduce the depth of the debossing (embossing is raising a material, debossing is lowering it).

The issue with this is that I've only heard of it being done on untreated veg-tanned leather, which your shoes almost certainly are not.

In order to successfully have the leather absorb the water, you'll first need to remove the covering. This can be done with a little soap and water, or (more drastically, and more likely to damage your shoes) with acetone or rubbing alcohol.

Once you've done that, stuff your shoes with something to keep their shape, and then soak + heat (a hairdryer or heat gun is the best option here).


You might consider using grommets, then lace it up. You can get a grommet kit for about $10.59 which includes grommets. They are really easy to install, and they actually look pretty cool in addition to their functionality.

https://www.amazon.com/gp/aw/d/B076BGJ7KB/ref=mp_s_a_1_1?ie=UTF8&qid=1516452247&sr=8-1-spons&pi=AC_SX236_SY340_QL65&keywords=grommet+kit&psc=1


How can I cleanly cut the inside of a paper on a different angle?

Using scissors, as you have pictured, would be a contributing factor here. Using a craft knife or something similar would most certainly be the go-to tool.

It is important to try to do the cutting in one motion - to not lift the blade from the paper and, if possible, not change the pressure you are exerting on the scissors. So if you were cutting this on a mat (without scissors of course), when you need to change direction you can rotate the paper accordingly. Craft knives have fine points so turning it is not likely to damage too much.

In the case of the specific Y, using a craft knife, I would also consider the starting point of the cuts to be the intersection shown and then cut away from that point. That approach is more case-by-case and really is dependent on your overall design.

If you insist on using scissors, the only tip I have to offer is to try and keep cutting as you are turning the paper. Try and finish the whole cut in one motion of the scissors. That would help stop the start of a tear. Hands and the tool itself can make that hard.


How is the string attached to this clear piece of plastic?

As you've noted, the thread passes through holes in the plastic sheet. The process appears to mimic the mechanics of a sewing machine. A loop is pushed through the hole to the underside. Another thread is passed through the loop.
Looking up "hand stitching awl" presents a method likely to be used in the photo collection. This method uses a single thread, while a sewing machine uses a second thread in a bobbin located under the machine arm.
For this project, the loop is pushed to the underside of the sheet. The awl is removed and placed in the next hole. The new loop is then passed into the previous loop and tensioned.
The new loop becomes the previous loop for the next hole.

From the above image, it appears that the underside thread is pulled mostly to the top. The underside thread is not visible on the underside, but it has to be there and may be the angle of the photograph.
A YouTube video shows one method of connecting the loops, although there may be other methods possible.


I can't find any information on what exactly foam erasers are made of, but my guess would be a microporous reticulated foam (like melamine foam, for example).
Foam erasers are universally lauded as being excellent in cleaning graphite off of paper, leaving (virtually) no traces, without having to put anything near as much power into the rubbing as one would with classic rubber, plastic, or vinyl erasers.
This also means you are less likely to damage the paper you're working on.
They produce larger pieces of waste material - with the right technique you'll be able to produce a single piece of waste, which means cleaning up is far easier to do.
There is no maintenance involved.
There is one caveat, however: as you write about the 'performance', we have to take into account the amount of material used in relation to the erasion power, and here these erasers fall a little short: being foam, they are consumed a lot faster than standard erasers.


How do I know I've got the right amount of moisture in the paper to wet-fold origami?

The amount of water to use will very much depend on the kind of paper you use. Thick watercolor paper can absorb a lot of water and still stay intact while copy paper will disintegrate or at least tear with even a little moisture. This behavior depends on the paper's thickness, fibre length and sizing. Most wet folding tips found on the web (e.g. about using a spray bottle) apply to thicker paper and not to copy paper. Personally, I have never been able to wet fold copy paper and be happy about the result - it comes apart with even very little water.

So, first of all, I suggest you get some watercolor paper, 160-300 gsm for a start. Such papers are widely available in artist supply stores and not terribly expensive. Canson Mi-Teintes is a popular brand that comes in many colors but others should do as well. Then, retry your folding sequence and you should see a huge difference compared to copy paper.

The exact amount of water to use is unfortunately a matter of practice, but when I started wet folding, I always used too much rather than too little. It is easier to re-moisten paper than to dry it quickly, so better start with a smaller amount. You have to remoisten as you fold anyway. For most models, your paper should be damp but not soaking. While 160 or 300 gsm paper feels very stiff and almost not foldable at all when dry, with the right amount of water added it should feel leathery and be able to roll along a smooth curve easily. For some models, you only moisten a certain area of the paper at a time rather than the whole sheet. Also note that moisture takes some time to penetrate the paper, so you should wait a few seconds before applying moisture and checking if the paper has the right properties.

The rest is a matter of experience, so start with thicker paper and give it a try once more.


What is the name of my drawing style? Black and white?

Black and white is the colour scheme of your drawing - it is never a style.
The medium is ink on paper, if digitally cleaned up and printed it can be described as a print (and you might want to consider working in (limited) editions).
The technique, depending on your drawing method, seems to be free drawing, akin to free writing (and in that case an intentional form of doodling), or 'automatic drawing', the drawing counterpart to automatic writing.
Since these methods usually produce an idiomatic decorative pattern (as user agarza mentions in the comments, it is similar to henna drawings, or mehndi), they can be used to describe a style as well, simply because it will tell people what to expect. But a better way to go about it is to see what makes your artwork yours, what is unique about it, and either combine that with 'doodling', 'doodles', or 'free/automatic drawing', depending on what kind of audience you want to appeal to.
For instance, your drawing also reminds me of a more abstract and asymmetrical and less geographical form of the luscious horror vacui ornaments and illuminations in manuscripts:

Gothic Ornament with Putti and Acanthus Leaves, 19th century.
Source.
Click for larger version.
Hence, 'ornamental free drawing' could be a way to describe your artwork.
Ultimately, you know best what you want to achieve and what kind of clients you want to attract, so play around with the suggestions given here in the comments and answers until you find something you think is appropriate for your artwork.


Only a few microwave ovens control the microwave power level on essentially a continuous basis.  That is, if you set the power level at 30%, the oven runs at 30% power output.  Most are based on turning the microwave power on at 100% for a given portion of a fixed time increment, like 30 seconds or 1 minute.  Then the microwave power shuts off for the remainder of the time increment, and the cycle repeats.

My microwave oven is based on a 30 second cycle, so the power level setting translates to 10% increments of 30 seconds.  At 50% power level, there is microwave power at 100% for 15 seconds, none for the next 15 seconds, then the cycle repeats.  If the time is set to less than the resulting power-on time, the oven stops when the time runs out.

So in my first example, with a 50% power level, the material gets 15 seconds of full power whether the timer is set for 15 seconds or 30 seconds.  In the second example, with a 20% power level, the material gets 6 seconds of full power at the start of the first 30 seconds, then another 5 seconds of full power before it shuts off at 35 seconds (almost double the energy despite the small time increase).

To get precise amounts of microwave power using the power level setting, you need to base it on the cycle time of your oven.  You can tell what the cycle is for your oven by listening to it cycle the power on and off and check the oven's clock to see the time between power-on cycles.  If you need brief bursts of microwave power, you may need to use a very low power level (and the process may take a long time).

The way the power level actually works makes it not particularly useful for short-duration requirements.  For those, I typically do what Chris H suggests in the comment -- do it manually at full power to get exactly the duration needed.  The main benefit of the power level setting is when you need a lot of cycles of short duration, and doing it manually would be tedious.  Understanding the cycle action lets you ensure that the duration at full power doesn't exceed a certain number of seconds at a time.


How can I unseal a bottle of glue that has been sealed shut?

PVA glue doesn't bond well with the plastic the bottle is made of; the dried glue peels off easily if you start at one spot.  It's harder to separate the glue and get the cap off when you're working against a lot of glue surface area at once.
If you grab the base of the cap with pliers, you can typically get enough leverage to break the glue bond and unscrew the cap without damaging anything.  Once it's open, you can peel the glue out of the dispenser tip and get any dried glue out of the bottle neck.
If brute force isn't enough to unscrew the cap, you can warm it to soften the glue a little, as Joachim suggests.  That will help it stretch and peel as you unscrew the cap.
Actually, depending on the glue, freezing it to make the dried glue harder can also sometimes help if the bottle is empty and you just want to save the bottle for reuse.  It makes the glue less flexible, so brute force can more easily break the bond.  But freezing can ruin any remaining good glue, which is your goal, so this wouldn't be applicable in this case.


How can we cut mirror or glass in a desired shape?

It depends on what sort of shape you're thinking of.

A convex polygon can be done with the scribe and snap method used for rectangles. This uses a wheel glass cutter or diamond scriber You should be all right up to an octagon at least, before the angles between the sides are too small.

Circles and large holes require a special tool

Small holes can be drilled and notches etc. can be cut using abrasive (diamond/silicon carbide/aluminium oxide) tools, usually wet, and usually slowly. These can be motorised (e.g. a Dremel or a drill) but hand tools are also available.  I've used a precision diamond saw to cut internal corners; this could probably be done using a cutoff wheel on a rotary tool.  Abrasives are also useful for rounding off corners and removing sharp edges (normal wet/dry SiC paper, a tile file, or a knife-sharpening stone)

Grozing pliers combined with scoring are used for tricky shapes, but I'm told there's an art to using them.

Note: links are to examples so you know what I'm talking about.  I'm not recommending specific products or suppliers. In fact a local hardware shop should have the wheel glass cutter and abrasive drill bits/Dremel accessories.


Is there a good technique or tool to keep long macrame threads from getting tangled?

You don't need to work with cord that spans the length of your entire project
You have a couple of options that depend on what aesthetic you are trying to achieve and what you are willing to accept as far as look.
Adding cord with knots
There is a family of knots used to add in new cords to your project. Mostly suggested as a means of adding more colours or something like a handle. Regardless this is to show that you can make changes on the fly. Something like the fisherman's knot you could use to start and stop cords.

Looking at the linked page above you will see many other knots. I only showcased the fisherman's as I am familiar with it as far as connecting two cords goes.
Beads
Only issue with adding cords is that you still have to hide the ends. None of the knots I found that are used in this way were accompanied with end hiding instructions.
From what I understand beads are used for flair. However you could easily hide ends inside the beads as well. If you tie a bead close enough to neighboring knots the bead will not be able to slide around. Then you can hide cord ends inside the bead(s). Gluing it inside the bead could also help.
Splice your ends
A better solution would be to splice your ends. You can do this with either sewing thread or, preferably, strands of the cords you are using.
If sewing: pin the cords ends with their butts facing each other to prevent them from moving and get proper alignment when completed. Get the first few stitches in, for stability, and remove the pins so you can finish.

It's same principle using the cord in the project. Pull out a strand and use that to bind the cord ends. Since you are using the same material you can hide the connection easier.

In either case you should stagger the cuts so that they don't all stop at the same point. This will help with the overall strength. Also, it will be easier to hide individual splices inside other larger knots.


The differences between masculine and feminine features to improve my portraits

I am no professional artist and don't draw any portraits, but I hope to offer you some insights free of prejudice and textbook mantras.

The woman on top doesn't look weird, masculine or ugly, she is just shaded unnaturally.

Light source

Every highlight and shadow depends on where your main source of light is positioned. In the lower drawing the woman is looking into the direction of the light source. In the upper drawing it's not clear where the light is comming from. Maybe to the left? Maybe in the direction of the viewer?

Shadows

The direct consequence of light is a shadow. In the lower drawing, the jawline casts a shadow onto the neck and the hair casts a shadow onto the jaw. Where both shadows combine it's darker than in other places.

Let's first concentrate on the left side of the upper drawing:

Her hair surrounding her forehead casts a shadow on her face but doesn't cast a shadow on her neck.
The hair in general looks quite natural with a flow of lighter and darker areas
The subtle highlights of her cheekbones and chin look very natural, too
The nose casts a shadow to both sides (but I know how f#ing difficult it is to draw a nose).

Now have a look at the right side of the upper drawing:

Most highlights indicate that the source of light should be in the upper left corner. The peak of her head should cast a shadow onto the hair on the right side, but there's a highlight instead.
Her right eye is brighter than the left one, as if the light shines from the right instead. BUT apart from that, the right eye is a perfect example of how it should look like with light comming from the left. You start with more details (more depth) on the left corner and let it fade into a smoth shadow to the right. Might be unintentional but looks perfect.
The cheekbone is again highlighted in a very natural way
On the jaw and neck light and shadows are reversed. The hair that is (probably) flowing over these areas is darker than the skin below. The perception of depth is absolutely destroyed and the hair looks flat or misplaced.

Anatomy

I cannot find any major flaw in anatomy in any picture. Maybe the ear on the upper picture is a little bit too high, but it's unmistakably a human ear. The round jaw and plush lips look very feminine and the proportions of the face looks about right. Good work.


How can I ensure my marker tips don't get destroyed?

I have seen children grasp markers in a clenched fist and vigorously fill in large swaths of the drawing area with colour. It's the vigour with which the children fill the area that destroys the marker's tip.

If this is what you are seeing then there are a couple of things you can try to help the children learn focus and finesse when making art ... and protect the markers.

Break up large areas into smaller ones

Never have an image which requires to be filled in all with the same colour. Say for example, an all blue table cloth is instead made to have a checker pattern. The smaller checker pattern forces the artist to focus on a smaller area. The strokes become more controlled and the child's hand movement is slowed. You see this being done in the adult colouring books where the image is intricate requiring the grown up to slow down, focus and concentrate in order to stay within the lines.
Teach them to hold the marker like a brush and not a pen ... or ice pick

Teaching the children to hold the marker as a painter would hold a brush will teach them a gentler way of applying colour to a surface. By changing the way the marker is held will reduce the amount of force being applied to the tip.

Another thing you could try is to have the children draw at easels instead of tables. Harder for the child to bear down overtop of the marker and drive it into the drawing surface.
Less abrasive paper

A heavy tooth paper should be avoided as it will abrade the markers foam tip over time. Try finding a paper with a slicker surface. One that will allow the marker to glide freely.


Making thin brittle sand design that holds together

Fascinating project. The solution was right in your question; make it like a cracker — flour.

You're essentially making a sturdy paste instead of a glue. I mixed:

3 parts sand
1 part all-purpose or bread flour
Water, just enough to wet the sand

I drained off any excess water, packed it into a mold and let it dry in the sun (1-2 hours?). I guessed at the proportions empirically, but it worked great!

The disc to the right is a failed experiment with cornstarch

The coin was pretty solid… yet breakable. I could carry it around and drop it from a few feet without breaking it, yet I could snap the disc with a bit of deliberate force, and crush it down into sand by pounding it or working it between my fingers.

  …after it is crushed it should appear as close to sand as possible.

Bonus that you're not adding anything permanent or inorganic to the sand. I could not see any flour when I crushed the coins back into sand, and dropping it into a cup of water broke it down completely (which makes it easy to pour off the flour-silt, if that's important to you).


Two things to consider:

Wood may soak up water and then swell, and glass terrariums/aquariums are not infinitely sturdy, so try not to have a straight piece of wood reaching from one pane to the opposite pane (your layout looks fine itr).
I you have an L-shaped glueing area (i.e. a platform plus a ramp, fitted together as one unit (the L being along-and-up) or a platform in a corner (the L being along-both-panes)) any silicone should be able to carry your platform and your hamster. So you could have the two edge platforms and then an assembly of the middle platform well-attached to the two ramps. No pillars needed.

Silicone can be removed from flat and non-iced glass perfectly with a razorblade.


Looking for a (non-yellowy) white chalk pencil for marker illustration highlights

I would suggest the Stabilo Carbothello Chalk-Pastel Pencil in Titanium White.

I found one for sale on Amazon for $3.84, here: http://a.co/gimVlHQ

But, I'm sure you can find it in most office supply and/or art supply stores.

There are several other brands, but I would seek out those pencils labeled, "Titanium White" to prevent the yellow-ish tinge you refer to.

Titanium White is known for being bright white. If you're looking for a more transparent, but also clean white, try to find a "Zinc White."


Can I make handmade invitation cards on a tight budget?

If you have plain white paper that is thick enough to make invitations cards, you can do the rest with free materials.

Cut and fold the paper into cards, then neatly write the invitation.
Cut decorative forms like hearts, lollipops, bonbons or Hello Kitty heads and glue them onto the cards. You can cut these forms out of colorfull sheets of ads or catalogs or anything colorfull you have lying around.

Catalogs for clothes or furniture often have single items printed very big (like a carpet, windows drapes or a t-shirt). The only disadvantage is that the pages are often so thin you can see the backside through.

An alternative is wrapping paper. If it's the birthday of your little sister, you probably have a gift to wrap for her. Use some scraps of that paper to decorate the cards. Pieces of gift wrap ribbons add a special flair.

Depending on what you have lying around at home, you can also repurpose things like confetti, glitter, small beads or golden makeup powder do decorate the cards.

Take care not to add too much to the card. 1 - 3 decorations are enough to make the card look special.


Is it really necessary to spray oil pastels with a fixative?

If you don't want the artwork destroyed, then yes. Any contact with unfixed pastel (oil or chalk) will smudge it. This includes contact through the plastic bags you're dropping the art into.
An artist-grade, archival-quality spray fixative should cause minimal color changes to your drawing, and proper handling will prevent any health issues.
In selecting your fixative, you'll want to evaluate whether it's designed for use on (oil) pastels, whether you wish to use it only at the final layer or throughout the work ("workable" vs "final" fixatives), and whether you prefer a gloss or matte finish on the final artwork. You'll also want to test your choice of fixative on a sample piece using your same oil pastels before spraying it on a finished piece, to ensure that there are no unexpected interactions between the fixative and your specific brand of pastels. (If you change brands, you'll likely want to repeat this test.)
As far as safety goes, you can check for an ACMI label of either "AP" or "CL:"

Products bearing the AP seal of the Art & Creative Materials Institute, Inc. (ACMI) are certified non-toxic. A medical expert evaluates each product and its ingredients. A product can be certified non-toxic only if it contains no materials in sufficient quantities to be toxic or injurious to humans, or to cause acute or chronic health problems. AP certification is reviewed by ACMI's Toxicological Advisory Board. These products are certified by ACMI to be labeled in accordance with the chronic hazard labeling standard, ASTM D-4236 and federal law P.L. 100-695.

Products bearing the CL seal of the Art & Creative Materials Institute ("Caution Label") contain ingredients that are toxic or hazardous, but they can be used safely with appropriate caution. Materials that bear the CL seal should be used only by those persons who are able to read, understand, and follow suggested safety precautions for handling those materials. The Caution Label signifies that although the product contains a toxic element, it can be handled safely if the directions on the container or packaging are followed. Many such art products cannot be made non-hazardous, but are necessary for certain creative activities.

(source and more details: Dick Blick Health and Safety Info
The primary health hazards you'll encounter with an aerosol fixative will be particulate and organic vapors. If you plan to use sealant frequently, you'll want to get a half-face respirator mask rated for particulate (N95+ in US standards) and organic vapor protection. You'll need to ensure the fit is correct, keep the mask itself clean, and replace the filter cartridges regularly. You'll also need to fit-test it every time you wear it (done by putting the mask on, covering the filters and inhaling to ensure no air comes in, then covering the exhalation valve and exhaling to ensure no air escapes), to be sure you've got it properly sealed.
While the specific hobby focus is different, this page has some excellent overall information on how to select and maintain a half-face respirator, with more detail than I've gone into here: Respiratory Protection (Note: this page duplicates a separate one blocked behind a registration wall on a private forum.)
Two key hilights from the page are:
Regarding particulate protection:

For sanding applications (including sanding of resin, apoxie and other sculpting materials, and wood), you need a respirator that provides at least N95 level protection. It should say N95 somewhere on the mask itself. If it doesn't say, it is not good enough. There is a scale to protection levels and anything above N95 is also acceptable (of course).
The levels are:
N95, P95, N100, P100

Regarding organic vapor protection:

The process of spraying releases aerosols (and this is true whether or not you are using an aerosol spray can product. Airbrushing paint creates aerosols too!) for which an N95 filter is not effective.
At this point, you will need to move into a mask that protects you against Organic Vapours AND has an N95 filter. This will mean moving into a half-face respirator.
Your respirator is no longer disposable and can be used again and again without ill effect; the only thing that will need replacing is your filter and (if applicable) your prefilter. Some respirator brands have an N95 filter built right into the Organic Vapour cartridge, but I recommend looking for one that does not, for ease of replacement. Cartridges and filters have different life spans and it is more economical to replace only the part that requires replacing (more on this below!).

If you want your work to stay in good condition, not smudge, and not transfer to the skin or clothes of anyone who brushes up against it, you'll need to spray with a sealant, but in no way does that mean you are going to "ruin" either your artwork or your health.


Do I need a non-photo blue pencil for scanning drawings?

Modern scanners, cameras, and digital editors pick up the non-photo blue pencil marks that earlier scanners did not. However, this color is still easily removed from the scanned image by switching to grey scale and altering the brightness and contrast. You could do this with another colored pencil pretty easily as well.

The answer to your question depends on what type of scanner and what type of digital art programs you use. If you have a modern scanner with a modern digital art program (Photoshop, Illustrator, etc.) you could likely achieve the same result with a normal colored pencil, as long as it was different from your final inking color.


The usual way to combine these 'squares' is to make many and stitch them together into a blanket.
In your irregular 'square' you may find they do not fit together well or at all in the usual pattern.
You can try out how the pieces fit together by cutting out a series of paper versions.
Select your pattern, make at least 10 realisticly shaped paper (or real) pieces and play around with them. Try using them at other angles as well. It may work to turn part of the pieces 45 degrees.
And do not forget that if you crochet them together you can make shorter or longer stitches, bridging bigger openings if needed.
And there is the option of combining 'squares' or different models. The one you show have points sticking out in the middle of the sides, there might be corresponding pieces which are having 'cut out' bits that would match.
Some blankets pieced together from crocheted pieces have bigger and smaller squares, it might be that there is a kind of matching piece in the book that is not obvious as the size is different.
And in the end, it is well possible that the writer of the book did ignore the 'making the blanket' as they did not intend these pieces to be actually used. Which does not stop you to be creative and still use them, but you will have to make your own matching pieces or filling connection patterns.
Alternatively, if you see a pattern in the expanding 'squares' you could keep expanding the single pattern till big enough to become a blanket by itself.


The rubber cement should just peel off the wood with gentle rubbing, provided it is dry. Using a piece of soft sticky rubber, and there are special rubber erasers specifically for picking up rubber cement, will help. Some shoes have gummy soles that are a similar material.

The use of rubbing alcohol may help remove any remaining residue but do not use it until you get most of the solid rubber off first and definitely test it on the finish somewhere not visible first. Starting with a solvent like alcohol without getting rid of the bulk of the rubber glue will leave you with a sticky mess.

fyi - This is actually a main feature of rubber cement. It is (was in this digital age) used in doing layout and paste up of text sides in photolithography. By only gluing one side, and letting it dry, the piece of paper with the type could be repositioned without problems. To make a more permanent bond, both sides were coated and then attached. The excess glue was then picked up with the above mentioned eraser


What make-up techniques could be used to achieve the watercolor effect shown in this image?

I suggest a basic sunless Tanner foam ( lightest tan)dispensed mixed with some color agent that won't dye the skin permanently, like a children's bathtime paints.
   Or, possibly use party streamers then either get wet to apply(an oil perhaps) or spray with body glitter for eye-catching gleam!
   Good luck!


This is completely a guess on my part...but I know that when I was taking a jewelry design class in the early 1990s, my instructor had to eliminate the enameling section of the class because the "ingredients" and techniques had just been determined too toxic to teach, and she hadn't worked with the new resins enough to be comfortable teaching with them.

So, maybe the big difference is our current scientific knowledge about the levels of toxicity that limits our access to the same raw materials that Lalique was using.


The glue might prevent this (depending on if the glue really is spread perfectly along all the edges), but a visual inspection should be enough. More likely is that the surface tension of the water will keep it from spilling over the edge.

If you are really worried about this and your technique requires huge amounts of water on the surface of the paper, you could apply some removable liquid frisket to the edges (available online or at your art supply store [e.g. windsor&newton]). Test it to make sure that the brand you are using does not damage the surface of the paper when you remove it.


Paint artwork on pressure treated lumber

There are aspects of the question that relate to paint, the material; painting, as in applying a coating; and painting, as in creating decoration.  I'll try to differentiate these.  In terms of paint, the material, there's a basic difference between a paint and a stain.  I'll use "paint" to refer to a material that coats the surface and dries into a "shell" of material, and "stain" to refer to a colorant that is absorbed into the wood.  That's an over-simplification, but close enough for the purposes of this discussion.

Dealing with pressure treated lumber

Pressure treated lumber stays wet for a long time.  The chemical treatment is forced deep into the wood and it can take over a year for the wood to thoroughly dry out.

Applying a paint-like material to pressure treated lumber isn't recommended, at least during the first year or two.  Covered areas prevent the wood from drying evenly (causing warping and worse splitting).  The more area that is covered, the worse the problem.  So a few tiny decorations would be less bad than applying a base coat to the entire piece.

Paint-like material doesn't adhere well until the wood is dry.  When the surface is dry but moisture is still high internally, you get blisters (domes) in the paint, and other symptoms.

The chemical treatment saturates the wood.  While the wood still feels wet, there isn't much of anything that will stick to it or get absorbed.  Even when the surface feels dry, while there is still high internal moisture, finishes won't go on evenly.  This is especially a problem for stains, and the larger the area, the more noticeable it will be.

Once the wood is dry to a reasonable depth, stain is typically the best type of finish, whether you're talking about covering all or most of the piece, or applying decorations that will be big enough to be visible from a distance.  It is absorbed into the wood instead of forming a surface coat.  There's a broad range of stain colors, and you could do some artwork with it.

Decorating the lumber

In terms of decorating the wood, if you want the decorations visible, you will need to contend with what will be the wood's color as the background.  Once the wood dries and weathers a little, it will be a medium gray when dry and can get dark when wet (and water will absorb into the wood, so it will remain dark for awhile until it dries out again).

Paint creates a solid surface color, so the visibility of artwork created with it won't be affected by the color of the wood.  However, you would want to wait at least a year before using paint for decorations.  Then you will have a problem of paint having a limited life on pressure treated lumber.  Pressure treated lumber doesn't age well when exposed to the elements, and the wood surface deteriorates under the paint, so the paint shell deteriorates.

Stain is much better suited for pressure treated lumber.  However, plain stain modifies the color of the wood more than creating a specific color.  So just applying stain in a pattern to create artwork won't be nearly as visible as paint.  There are a couple of things you can do to improve the situation.

One is to first apply a background coat of a very light color.  You can either apply it to the entire piece as a protective sealer, or just as a background in the area of each decoration.  Bear in mind that stain works by being absorbed into the wood, and most stains you'll find for outdoor use also seal the wood.  The heavier you apply the base color, the more effective it will be at making the background a light color, but it will also seal the wood more, so the colored stains you apply on top for decoration won't absorb as well.  It's a tradeoff.

One other consideration, plain stain is a very thin liquid, which will be runny, especially working on a vertical surface if you decorate after the post in erected.  It will be even worse if you seal the surface with a base coat.  So you will need to control the amount you apply.  You will have a mess if you try to apply it heavily.

A better solution is to use pigmented stains, often referred to as solid color.  Pigmented stains are a mix of stain and solid particles of color.  The liquid gets absorbed into the wood and the pigment stays at the surface, making the color more intense and opaque.  Pigmented stains are closer in consistency to paint, so easier to control when you apply them.  You wouldn't need a color base coat for pigmented stain, just apply it to create the artwork.

Another potential solution (I haven't personally tried this): use a light color pigmented stain as a base coat, perhaps on the whole piece as a protective sealant.  When it is completely dry, paint the decorations on it with oil base paint.  That might work better in theory than in practice; I have no idea.  You could try it on a scrap piece.


Can an artist use graphite powder made for dry lubricant?

Yes, you can use it if you're careful about the material and the purpose.  Graphite, itself, can be purchased virtually pure.  It's available in different particle sizes, but the typical graphite powder used for purposes like lubrication is also fine for art purposes.

You need to distinguish between pure graphite and graphite-based materials.  Graphite-based materials sold for one purpose may not work well for a different purpose because the material is a mix of graphite and other stuff designed to optimize the mixture for a specific purpose.  So, for example, dry graphite lubricant powder may have other materials in it that will interfere with the properties you want to use it for.  Look for material described as pure graphite.

The product description will often include uses the powder is suitable for based on its particle size and purity.  For example, this product from Amazon describes that it is suitable as a lubricant and a pigment for resins, so I would expect it to be generally fine for other art purposes (although you may need to mix it with other ingredients for some purposes).

As far as safety, graphite powder in a particle size used for art is extremely fine stuff that easily gets suspended in the air.  You don't want to breathe the dust because it can be harmful to your lungs (and what gets into the air will eventually settle on surfaces and make a mess).  You should at least wear a good dust mask or N95 mask, and it wouldn't hurt to set up a HEPA filter, or vacuum cleaner with a HEPA bag, to draw in and filter the air in the area where you work with the loose powder.


"round brilliant"
Round is the shape.
Brilliant is how the gem is cut.

  The modern round brilliant consists of 58 facets
  Wikipedia

Gemstones can be measured in different ways.
Three measurements: Length x Width x Height (depth) for oval or polygon gems
Two measurements: Width x Height (depth) for round gems
Sometimes only one measurement is given: Width. i.e. 5 mm round / square gemstone

  Round gemstones should be symmetrical with a perfectly circular outline. However, in practice, a good percentage of gemstones are native-cut without the use of precision lasers and other advanced lapidary tools, so many round gems are not actually perfect circles and are rather better described as being near-round. This is why you may find that many still use three measurements for round gems. gemselect.com (not an endorsement of their store or products. Information only)

Bottom line: To get something the same size as the stones you have you will need to measure them and then look for stones with the same numbers.

Mass produced jewelry settings come in standard gem sizes. Some makers will cater to these sizes and make stones that fit. If the stones you have are a standard size you increase the chances of finding matches.
Note: the linked standard gem sizes chart shows a size by weight. The chart is for diamonds - other types of stones will have a different weight to size because they have different densities.

Even if you find something with the exact same numbers different makers will have different tolerances and have different levels of consistency. You will have to decide how close is close enough.


How to draw a heat blur from an aircraft engine

The heat blur effect is caused by the hot exhaust chaotically refracting the background. That is, the noisy turbulent hot air of the jet blast bends the light coming through it randomly, leading to blurry areas where the trail is. So to convincingly draw the heat blur you would need to have a background to be blurred.

That being said you could represent it by drawing the exhaust trail itself and slightly distorting the areas of the jet it overlaps. Since you are showing a heat trail and not a smoke trail you would want to go very light with the drawing in terms of tone and density. Try using fine lines and shapes that capture the jet trail's swirling movement.


The basics of this can be pretty easy if you want it to be. Getting the exact desired effect, much like anything in crafting, will take some experimentation.

In its simplest form put down you base paint i.e. the colour you want to see below the peeling, distress and etc. Then put down something to help prevent the next layer of paint from binding. White glue works well for this. You would not necessarily use glue on your entire surface but where you want the cracking / peeling to occur. In your case you can try and target it along a line to simulate broken wall or foundation or something. How long you let the glue dry before you put on the next layer of paint is subjective. Most seem to wait until it is tacky to the touch.

Next you would put on your top layer of paint. The choice of paint should not matter here to much either. A milk paint lends easier to distressing or chipping. You see milk paint used a lot in "antiquing" furniture.

Once that paint is dry it should have cracked on its own while drying. If that is not to your satisfaction you could use some tools to help it along. Utility knives, putty knives would be obvious tools of choice. Again, you would need to experiment to get your desired effect.

Aside from the above or possibly in conjunction I have also seen people accelerate the drying process with something like a heat gun / hair dryer. This will definitely help the peeling process via bubbling. Take caution as to not burn or melt the paint.


That was made by a triple needle chain stitch machine.  You can tell it was done in one pass with a triple needle machine because the holes align perfectly along the length of the stitch (making it very likely they were all formed at the same time).

You can tell it's a chain stitch (as opposed to a lock stitch, which a typical household sewing machine makes) by the way the stitches are formed on the back.  Another common place to see chain stitches in your house is on jeans.

The main advantage of chain stitching (and the reason it is used in commercial applications like this) is that it doesn't require a bobbin.  A home sewing machine is a lock stitch machine, which means the top thread is twisted around a bottom thread by passing over the bobbin on each stitch.  The bobbin is limited in size because the top thread has to go around it.  A chain stitch machine can sew much longer without interruption.

In particular, I think I see three threads on the back, which is a double chain stitch.  Those extra threads don't actually add any strength.  More the opposite -- chain stitches can easily be unraveled if the thread breaks, just like pulling apart a row of knitting.

If you want to recreate that seam, just sew three times with your home machine on straight stitch.  You won't be able to recreate the stitch length (your home machine just won't make stitches that long), which will cause a bit of extra puckering (shortening along the seam).

By far more important than exactly what stitch you use is to use a good bonded polyester thread or an outdoor item like a hammock will fall apart when the thread rots.

(If you want to see an industrial machine that could do this, Google something like "triple needle six thread chain stitch".  Six threads because it's a double chain stitch.)


Keep yarn slack from developing in my work as I perform a basic knit stitch

From the image you've shown it looks like you're on the first row of knitting after casting on, and it also looks like you've used a loop (a.k.a. backwards loop) cast-on method.

It's common to get an ever-increasing amount of slack on the first row when using this kind of cast-on. A loop cast-on is easy to do, but hard to do well because the tension used when casting on is fiddly. If you keep knitting this piece the knit stitches will even out, but they might not even out completely.

I recommend starting with a long tail cast-on. It will take a little longer to get the hang of, but you won't have the slack problem.


How to repair (sand down) the sides of a paperback book properly?

When working on the cut edges of a book you need to clamp the pages of the book closed between boards. Making a 'board book board' sandwich.
Ideally the boards are as big as the pages of the book and you can clamp them just around the book with separate clamps.
Which in turn you can clamp down in a vice, to hold it for you working on it.
It is also possible to skip the clamps and position the book in its boards in a vice but it is harder to position them right in that way. Even when for working you should not have clamps, it is often good to clamp the work before placing it in the vice and take the clamp off when it is safely in the vice.

If your boards are bigger or smaller than the front and back of your book, you can still use them but you have to be careful to position them such that the edge of the book you want to work on is. supported and not work on any part which is not supported.

If you want to take a bit off the book, you can have the book stick out of the boards a little, but often it is easier to take a bit of the board along with the bit you want to take off the pages.

When the pages are clamped in like this, they should not be able to puff up, but you should still work in such a way the paper of the book can not get wet at all.

If with this way of working you still have problems with 'puffing' please add photos and a good description of the problem.

The book binders I have seen working all used a knife to cut the pages to size, with the books clamped in between boards, not using sand paper, but they do take off more than you seem to want.


What is the name of the drawing having free hand shapes of animals, birds, flowers combined together to form a pattern/story?

I would classify these images as line art.

With line art you will see clear lines defining forms and shapes, and sometimes where color and light would be, but the color and shading won't be there.

Definition is enhanced in compositions such as the ones posted by varying the line weight and and stroke. The thicker lines make parts stand out, and also help define depth.

Since the line weights vary in these examples, they may have been drawn using some type of ink (presuming they weren't digitally produced). Pen and marker tips allow for more variation in line weight than a typical pencil, although it's possible to sharpen a pencil in such away to allow for more variation.

Line art itself isn't going to be subject to less rules of composition than other 2D visual arts. An understanding of composition in general is going to be helpful, although outside the scope of this answer.

However, certain techniques or media may be more helpful to practice with, if the end goal is this type of art: Drawing in general, inking or other practice to help with line weights, and making clean lines.

Making clean lines can be achieved by learning how to use such tools as French curves, templates, stencils and compasses:

Here's an example of some French curves:


When considering the compatibilty of coating materials, the intended use (jewellery) is less important than the base material.  Nail polish/paint sticks well to some materials and not others. Without knowing what your "white" jewellery is made of, we can't tell you whether it wil stick well.

It's not really designed to be permanent, so I would advise against it for pieces that are meant to last.  For temporary modifications it could be excellent, with caveats. Although it will chip fairly easily, there will be some bits left. Getting the last traces off is easy on metal/glass/stone materials (using acetone), but if there's any plastic or glue the acetone (nail polish remover) is likely to damage that.


Polystyrene is attacked by many organic solvents, so I'd rule out all solvent-based glues you haven't personally tested.  Different compositions can be sold under the same name in different countries, or can change over time, and very similar names can have different ingredients.

That leaves you with two options; I recommend the second:

Water-based glues: These will give you a low-strength bond on polystyrene, but if you have a large area of a fairly  weak material that might not matter.  PVA (white craft glue, wood glue) would be one type, latex (e.g. Copydex brand) would be another, but you'd need to be sure you were getting a water-based  product (many other glues with latex/rubber in the name are solvent-based).  You'd need to use a thin layer, and drying times would be longer than expected, because you're relying on water  evaporating and it has to escape.

Hot glue: Cool melt hot glue is plastic, which is melted and applied to one surface.  This sticks well to polystyrene.  It cools and solidifies fairly quickly when exposed to air, but extruded polystyrene will keep the heat in, so setting times will be increased.  As with water-based glues you'll have to support the workpiece while the glue dries.  This should give a stronger bond, as it is better able to fill the gaps in the surfaces.  You can get a range of colours, but don't expect to colour-match.  With decent pressure as the joint sets you can avoid gluing right to the edge; with a suitable colour the join can be subtle.


Methylene blue is a very effective water-soluble blue dye and you can buy it on amazon quite cheaply (the pack at that link is probably enough to dye a table and chairs). That might do the trick. It's also used for treating fish in tanks, so is quite benign.  The question becomes one of whether the water raises the grain too much given that the dyed layer is likely to be quite thin. It's also soluble in alcohols (including isopropanol, so surgical spirit/rubbing alcohol) which wouldn't raise the grain.

I've done a quick test on a bit of scrap softwood using something like a 0.7 mmol/l aqueous solution (0.2 grams per litre of water).  It was brief enough to not raise the grain even where I left it on the longest:

I've adjusted the colours to look about right on my screen. The wood was quite old and yellowed.  It had just about dried when I took the picture.

The left for 1 minute test was meant to simulate dip-coating.  I didn't hold it very steadily, so the unevenness below the "p" in the annotation was casued by the solution running.

It could work nicely, but you would want to make sure the wood is very white to start with, and stays that way, to keep it really blue instead of turning greenish.  This is probably true for any blue dye. This article on bleaching wood implies that you can bleach the original wood with the right wood bleach, then neutralise and rinse and there shouldn't be any bleach left to react. Here's some more discussion on bleaching and coating so it doesn't turn yellow; in summary: use a water-based varnish over the top so the varnish also doesn't turn yellow, though pine will yellow slightly whatever you do.

Of course, test as much as you can on scrap (and the same type of wood) first, in particular if you decide to bleach then dye.


Can I cast a glow in the dark flower in resin?

A few comments about the problem as a whole, before I address your specific question...

You are attempting to encapsulate something in a clear resin shell.  That shell lacks any distinct shape, being comprised of flat planes and soft organic curves.  It does not contain any sharply detailed features or surface textures.  In short, the shell probably does not contain any aspects which need to be captured by an advanced casting medium like silicone.

Consider Casting a mold using a mixture of Gelatin/Glycerin.  This avoids much of the cost of casting silicone.  Silicone is better in my experience for capturing details, but for your project, gelatin will probably work fine.

On a different subject, clear resins are notorious for capturing air bubbles which may detract from the look that you are pursuing.  There are techniques for reducing those bubbles but the only way to completely eliminate them is to use a vacuum chamber.  Here are some instructions on creating a cheap vacuum chamber.

Now for your actual question...

The containers which you show are suitable for holding your mold.  I prefer the red Wall's container because it seems to widen near the top.  That will make removing the mold from the container easier and leave the container intact between castings.  That way, once you have cut your original out of the mold, you can return the empty mold to the container to support its original shape during the application and curing of the resin.


Using colored pencils, is it better to ink the outline, or start coloring over it?

Color pencil considered as a light to dark application, thus tracing your initial sketch with any dark medium will ruin it (they will be visible beneath your painting, unless you intentionally want to do so like mixed ones) . So in my opinion you definitely  should not do that. Try to keep your pencil sketch as light as possible, barely can be seen. Then start with the lightest color / value and least pressure, continue by lying down darker tones gradually to build up the painting.

You should preserve the light from the white of the paper or cardboard and you always can go darker but using an eraser will disturb both your pencil marks and the surface texture.


It looks like you could blow up a ballon to get the shape of the interior.  Then glue hex shaped objects to the surface of the ballon in the pattern of the holes.  Then build a wire framework over the tops of the hex shapes to hold them in position and to support your mold's outer shell.  Finally apply that outer shell as a series of glued vinyl sheets or paper mache.  Once that outer shell is dry, you can reinforce it with clay or silicon.

You should then be ready to pour in the liquid clay.

This will be a sacrificial mold, so you will mostly need to destroy it to get your casting out.  To de-mold, remove the reinforcing material and paper mache, then the wires.  Then pop the balloon and push out the hex shapes.

The exterior of your casting may have some lines from both the wire framework and any seams in the vinyl/paper mache.  It might also have bits of vinyl or paper mache stuck to it unless you washed the interior of the mold with lubricant before adding the clay.  Those problems should all be pretty easy to fix with a little sand paper.


What's the name of a concept where objects take on forms out of different things?

Optical illusion

According to Wikipedia, this is

  an illusion caused by the visual system and characterized by a visual percept that arguably appears to differ from reality.

In the first two photographs (making it '(optical) illusion photography'), this 'visual percept' is a flag. Here the 'illusion' is caused by the (careful) positioning of objects in alignment relative to the point of view.

Another term often used is for this is 'forced perspective', which is a type of optical illusion.

Though the illusion is not as monumental as the word suggests, it functions basically the same as works like this one, the Triumph of the Name of Jesus by Giovanni Battista Gaulli:

This example is another sub-category of those optical illusions, referred to as trompe l'œil (from French, meaning 'fooling the eye'), a term which is almost exclusively to paintings. It is often used in conjunction with architectural forced perspective.

Our perception tricks us into seeing more than the sum of the parts (like depth, light, &c.).
The construction of (linear) perspective is also based on this principle.