| Re: cutting plastic?
I make my jewellery from the shrinkies stuff. Use the clear sheets, ANYTHING works on them but I use projector pens coz they're good for drawing in detail. You can do other cool stuff with shrinkies, I scratched in some designs with a scalpel before baking and ended up with really nice frosted look plastic.
edit: if you can only find black sheets to work with then I've been able to use crayon eyeliner on them(i only used white though so couldn't tell you if all colours would show up well)
also, the package will say to draw 7x larger but DON'T. 3x is more accurate. | 
