US source of thin polypropylene sheets?

I'm looking for sub-mm thickness polypropylene sheets for use in plastic origami projects - sort of like the Orikaso folding dishes and polyscene's work. I need sheets that are at least 14x14" without creases. Colored stock would be great, white is just fine - but black won't work. So far I've struck out with the local plastics fabricators, signmakers, and printers, but hope springs eternal - any suggestions would be appreciated.

brossa (author) 7 years ago
Mind you, that lead came after running through pretty much every iteration of "x micron polypropylene" from 500 down to 200, and every iteration of "x mil polypopylene" from 30 down to, you guessed it, 9 mil.
brossa (author) 7 years ago
I've been looking for large 'gift bags' of polypropylene - the heavier, boxy kind, not the plastic grocery bag kind.

Perhaps better yet, Googling for "9 mil polypropylene" has produced a lead: banner rolls. 9 mil is 228 microns, so it's in the right neighborhood.
brossa (author) 7 years ago
Thanks for these links, seandogue - I should have included that I'm looking for thicknesses in the 200-300 micron range, or 7-15 mil or so. K-mac has large minimum quantities in that range; if there are other suppliers (or end users?) I'd love to hear about them too.