When it’s coated with plastic. Like the kind I have to hide from Arya because things like this happen…
Two years ago, in my post about plastic-free kitting, I mentioned I was knitting slippers out of Superwash wool from Lorna’s Laces. I assumed that Superwash meant the yarn had already been washed and wouldn’t shrink anymore. I guess I was thinking of cotton. Anyway, an astute Fake Plastic Fish reader Rebecca left a comment on that post just a few weeks ago letting me know that Superwash wool is actually coated with a polymer to prevent the wool from shrinking. (It’s nice to know my posts hold up over time.)
Turns out, there are two methods used to create this stuff. According to About.com’s article on Superwash wool,
It can be made using an acid bath that removes the “scales” from the fiber, or it can be made by coating the fiber with a polymer [read: plastic] that basically keeps the scales from … Read the restRead the entire post.