I find the blades seem to last longer on self-healing mats, plus flip them around, you might get a bit more life out of them. What I do with my used blades is sharpen them and then use them in my rotary cuttery for paper only. This way I get another life out of them before I toss them. I keep the little containers the blades come in and label them for "to be sharpened", "sharpened", "toss" All my rotary cutters are labled too and god be with you if you use a cutter for something other than what the label says.