During a recent class I had several students who were trying to use the rotary cutter to cut 2 1/2″ strips for a quilt. The ruler kept slipping and the strips were cut crooked. I have experience using a cutter and ruler so completed their strip cutting. I then went shopping for something that may help in the future keeping the ruler from slipping for beginners cutters who are not used to how to apply pressure to the cutter and ruler. I found it with InvisiGrip. I applied the thin cut membrane to my ruler and it worked. The students loved it and there was no ruler sliding and slipping. I recommend this product to everyone!