I thought it was just me. I got an elecric blade sharpener and I thought it was good until. . . . . I purchaded an "ergonamic Martelli"rotary cutter. Wow, the difference was amazing. It came with a blade and it cuts like a hot knife through butter. I did 4 layes and there was no effort at all. No strings stubbornly refusing to be cut. It would be worth it to me to buy better blades. Anyone know if these come is a 5 pack? I finished the first project and it's still cutting like brand new.