my wife had a fleece processed into rolled batts. My experience with it was it compresses very nicely into hard nasty little clumps that stay that way for the rest of eternity. Wool yarn and thread is already compressed into controlled matts which is why wool cloth does not compress any more. Once the thread or yarn is spun it is very stable and doesn't change much, at least until it is felted. Warmth to the nth degree with that stuff. But just plain wool batts would concern me. But hey... try it...