What is this called

[TankerDriver]

They are made out of a wooven cotton type paper, kinda like money, but stronger. If anyone has ever used a fan-fold checklist in the military, like the one we use in the KC-135, it's pretty much the same paper as that. It's very strong and water proof.

 

[Pirate]

I think it's Tyvek; the same stuff they wrap houses in to keep water out.