sobaboo; I find my cutters work best on at least 4 layers of fabric, rather than 1 or 2. I believe that was what they were designed for, way back in the dark ages of quilting. Cutting tracks on an older the mat can also cause skipping; flip it over and use the second, smoother side. Use your ruler for measuring strips and squares, not the grid on the mat. I use the mat grid strictly for squaring/straightening a length of yardage. Hope this helps you :-) :-)