I got my first Xcelite tools in the late '60s. That set was given to me by another GI when I left the service. I was mad that he spent $50 on a gift, but it sure earned its keep.
I have had a lot of different oils get on it, along with brake fluid and numerous solvents.
I'll cut some test strips when I can get to the assorted chemicals in the garage.
The only documentation I can find on the material i get is a low flammability certificate. Considering what little it costs me, and what I intended to use it for, I really don't care. I was offering some small pieces for whatever use, and for what it cost me to ship it. As far as I can tell, there are three types of sheet and one of the screening. They won't give me any details on it, other than complain that their US supplier when bankrupt and how hard it is to purchase & import. They have to buy each color by the pallet load per color. They used to have about three dozens colors available but now its only a half dozen at best.