It looks like cardboard, actually...very thin(ish) cardboard.
Not really correct here...they aren't "soaked" in steroids, but rather the chemical powder is sprayed onto a layer of cardboard (paper, I suppose), and then allowed to dry after another piece is placed over the top. So what you have is a thing that looks like piece of thick paper, I guess. Kind of more like very thick construction paper, thicker than the cover of a magazine, actually.
And they aren't perforated, either....never have been. They are marked off into equi-sized rectangles,, and you cut along the lines with a razor or sizzor, and then you have your 100 doses per sheet.
I've used them, and they work. I doubt he has experience with paper anabolics (he seems not to know what they look like), so he's probably doing his best to relay "information" he's gathered "elsewhere"... ;^)>
They seem to be a bit defensive, on both parts, with more flames and insults than real information being produced or discussed. JMHO.