It's an interesting question... What the heck IS polyviscose? Truth be told, I never even heard of it until I became a member here. And a quick Google search for the word links to XMarks as the number 1 hit, with little else offering any further information...

I do however know viscose. It is used in making rayon. When I was still in university, I did a science project for my organic chem class where I actually MADE rayon fibers by squirting a chemical slurry through an injection needle into a reactive bath, causing fibers to be formed. (Gotta toot my own horn here... I won that contest, improving my course grade by 10% and receiving a brand new scientific calculator as my reward)...