I ordered some Plyban from Hoegger. I was expecting something plastic or resembling plastic. According to their website, there should be two 18 inch by 22 inch sheets per package. I ordered a triple pack, so I should have six 18 x 22 sheets.
It looks and feels like thin fabric cheesecloth or muslin to me. It appears very clean looking, like it was pressed, but each "package" (plastic bag) contains one sheet of multiply folded fabric (folded just like regular cheesecloth) that is 40 inches by 74 inches. Roughly 2960 square inches, or 2.28 square yards. Their muslin is described as 2 square yards per package, so this seems to fit.
Anyway, since I've never seen plyban, I don't know what to expect. But I believe this isn't it.