I've created extruded objects and they don't seem to behave correctly I've just started picking up blender for some projects at work, and am hitting a stumbling block. I'm building a fairly mechanical object and as such have been creating it in layers, using extrusions from paths. All this seems to have worked fine however when I'm now trying to use a boolean to "cut" holes into them, it leaves open holes into the object. Attached are some images to try and illustrate what I mean.







My overall Object/project
Here you can see me selecting my boolean modifier
Here we have the result. Weirdly, it seems to add it
So I go ahead and delete the extra faces, and I've got holes aplenty


You can see on the front of the first image a boolean that I used to cut away a cruve from a block that worked fine, so I'm stumped.

I wonder if it has something to do with my objects being blue rather than grey, but I don't know if this even means anything.
Okay, I managed to figure it out. Basically all the faces were facing the wrong way on these extruded objects. So, opening them in edit mode, selecting all the faces then hitting Ctrl-N cleared it up, and the booleans are now working properly!