I suspect the linen was layered with horsehide glue. I saw it being used to lay up layers of thin wood veneer when I visited the Steinway piano factory. Basically they make Micarta out of it (layers of paper or cloth glued together with thermosetting resin and then heated and compressed until it cures. Used for knife handles, similar craft products. I think the process originated in airplane manufacturing. I suspect they're using the technique to make blades for wind generators.

I can do simple prestidigitation (palming a coin) and I know a fair bit of guerilla chemistry (having once read Abby Hoffman's Steal this Book. I could probably develop a decent career out of using electrical tricks to convince people I'm a powerful sorceress. I also know a fair bit of midwifery and general first aid. And I have a lot of ability to improvise food from random ingredients. In a quasi-medieval setting, I could do a lot of Crone things.