I have a cutting mat that's about 2-3 years old now. It came rolled up, and I couldn't get the waves out of it. I took it outside in the summer on a black asphalt parking lot and left it there for several hours. Brought it back inside, it laid flat as a pancake. It cooled off, back to the waves. Still 2-3 years later, it still has a couple places in it that won't lay flat. I have used banner hem tape, I have heated it with a heat gun, I have done everything I can think of and I can't get the waves out. I saw the guy at a
sign show that we got it from and talked to him about it and he said every so often that get one that will not lay flat. No one knows why, and nothing seems to help, but it does happen.
If you figure it out, let me know. I'd like to resolve this before I die
