I have no idea how it got warped. I place them length wise up against a wall, with the blade side backing another die-Just as you would if you had the die holder, which is a large, more sturdy letter holder. The first one I bought came warped but it took me a long time to realize that - much lost money on fabric. That one was replaced at no additional cost, but I have had this current one for almost 2 years now so know I can't get it replaces for free. I am so upset, because they are expensive. Sorry to complain so much. Just a bad day.