Ive had a couple nick, and when they broke (always the black string) I simply brought it to home slepot and they said go grab another one. No paper work, no hassles, home slepot honored the lifetime gurantee! I tried to replace the black string with zing it, only its held in place with a stopper knot. That eventually pulled through, and after the hours it took to understand and fix it the first time, I said screw it and brought it in to be swapped out. Home slepot has replaced every fiskar tool that I have ever bought and broken.