nylon paper?

Warning: dangerous nerd overload ahead. Proceed at your own risk.

I found – possibly serious quality – textured plastic paper – at least Walmart says that Bienfang watercolor paper is nylon, 100%. The FedEx guy just brought it and I swear it’s cotton. Below, with my peach gum homemade watercolor, I sketched an apple->

bienfang apple
click to enlarge (I erased highlights)

I erased all those highlights on the apple; used a flat brush to lift orange yellow below.

It’s lightly textured, 140lb / 228gsm, cold press. Nice and firm paper, cottony feel. But indications that it is nylon: 1. It dries slowly, apparently by surface evaporation only. 2. My staining pigments can be lifted.

The texture is light, meaning I can still draw on it. Yet I can also lightly scumble. So far, warping settles back down when it’s dry – too soon to know. The paint is nicely bound to the paper. Washes seem controlled, but again, too soon to know.
I can take my eraser and erase the paint back to the paper! Often completely, sometimes only partially back to pure white. (phthalo blue, quin magenta, hansa yellow)
The only flaw is scuffing when I scrub. It scuffs especially badly when the paper is still wet.
For only 33¢ ($0.33!) per sheet, I think I’ll learn not to scrub.
If it is nylon, I’m just head over heels in love with it. I’m puzzled as to why the maker’s website doesn’t list the material. 13th down in this page: http://www.speedballart.com/our-products.php?cat=12
Shouldn’t they be advertising that proudly? Hey, this lasts forever, we’re the definition of archival; we ain’t no polypropylene Yupo, we could make slippery Yupo cry?

Maybe it just has a lot of surface sizing.

I just emailed their customer service.
19th of July: I received this answer: “Thank you for using Speedball Arnhem paper. It is 100% wood fibers that are archival.”
Um, it doesn’t say ‘Arnhem’ anywhere on it. But I would vote for wood. I had already torn a piece apart. Darn you, Walmart.

OK, after another interchange from the Speedball representative: “Bienfang Watercolor paper is rag or cotton fibers.”

So, I suppose it has a lot of external sizing. I really like it after I stretch it or paste it to board.
Notes to self: 1. Student grade can be fine. 2. Stop impulsively posting. Slow down and verify.

Later in the day: representative wrote back: “I was corrected on the watercolor paper.  It is wood fibers – not nylon.”

I’m going to go be confused now.