This is a real good topic of rotary blades and how long they last. Someone just gave me a little rotary cutter sharpener and I haven't used it yet. Like most I hate blades that start skipping . I've had them skip when I hit a ruler by mistake and tossed them out. I try to buy them on sale. But I have to get that sharpener out and try it as I hate to buy more blades. When I do buy them they have to be on sale. They sure beat making sandpaper or plastic templates.