I had a problem with my 10" square mat with the large tumbler die. I called the company and asked if it should be expected to last for more than just one queen size quilt (which I hadn't even finished cutting). She said absolutely it should last longer and they sent me a new one free of charge. I told her I was labeling the mat 1, 2, 3,4 on one side and a, b, c, d on the other so I could keep track of the rotation. She said she thought that was a good idea and she was going to pass that on to other customers ... btw I did not buy the mat from them but they stood behind it anyway!