I finally used the rotary blade I got from Threadart- Wow!!It is like a hot knife cutting though butter--so smooth and quiet --you would wonder if you had the fabric cut at all but when you check-no threads showing smooth as silk. Worth the $2.99US I paid for them. Now I have 10( gave DD two) I am happy about that, being a pensioner and getting them when I did helps me save a lot of money on fabric.