Rotary cutter. A few weeks ago, I asked my husband if he knew how to sharpen "something like a pizza cutter" on a regular knife sharpener. He said he would try. When he gave it back to me, it didn't cut badly - it didn't cut at all any more. So for a long weekend, I had to cut with only scissors. As it turns out, I'm not very good at cutting straight lines with scissors. Fortunately, I now have a new rotary blade.