Funny but I just read a comparison of a wool mat and a homemade plywood, batting, cotton, foil pressing mat. The author of the article said she saw no difference between the mats and that if you use steam on the wool mat, it smelled like a barn so don't do it. She mentioned that using steam with a h-o-t iron would scorch it which is exactly what I had happen. So, just be careful out there when using a wool mat ... or maybe build one out of the previous mentioned items instead.