Okay, here we go. Paula Fullager sent me 3 blades to try out. Man!!!! I couldn't cut ANYTHING with any of them. There must have been a bad batch made!!!. I have never had any that bad. I tried 2 different rotary cutters. I have an old Kai Cut one, the center hole is a little snug, so then I tried my Olfa cutter. Still wouldn't cut. Next I got out a new pack of blades I got a few months ago, WOW what a difference, cut like going through butter. I would say to all of you that have bad blades to take them back to the store and COMPLAIN! They will never know a bad batch came through if we don't complain. I don't see how those blades would even cut carpet, they are so bad. You can feel flat spots as it rolls along. If it won't cut 100% cotton, it won't cut anything. Thanks for allowing me to test them out. Conclusion: RETURN YOUR BAD BLADES!!!