Beside the mat underneath some fabric is not very goof with blades. I find poly and thicker fabrics cause problems. Perhaps a look at sizzix or the cutters would end up bet ter for you although one are cheap.
Quilting"
Mats and cutters expensive and need replacing sometimes.
Fabric getting more and more expensive .
Notions expensive.
Scissors guard with your life ONLY FOR FABRIC.
OH BUT IT IS SO RELAXING, THERAPUTIC, GREAT FRIENDS TO MEET , AND ADDICTIVE
Will stop the cleaning, cooking and soap thrills .
Keep quilting and enjoy all these wonderful things all wrapped up in cotton fabric.