craftgrrl | Hey all! Shrink Question (Reply)

Hey all! I won't write a novel but go straight to the question :)

Where is a good supplier (even wholesale) of shrink plastic?

I know clam shells of #6 plastic work, but they are so small and have a lot of waste on them for this sort of thing. I would like whole sheets, preferably that can be used by hand or with a printer.

I remember buying them in the '70s but these days they only seem to be in specialty (and expensive) shops now in smaller amounts.

What materials work best on it for coloring?

I know sharpies work, but what of stamping inks? Colored pencils? Etc? (not counting the ink jet ones that obviously work with printers) It would be neat if I could stamp and then custom color little stained glass bits, as well as be able to do my freehand art, or digital projects.

Thanks!