This double-sided Creative Grids Self-Healing Rotary Cutting Mat is 12 in. x 18 in. and designed by Gudrun Erla of GE Design. One side features one-inch grids with eighth-inch markings over the entire surface. All numbers are printed outside of the grid area, so they are always visible. Popular 1-1/2 inch cuts are highlighted with white stars; 2-1/2 inch cuts with white squares. Eighth, quarter, and third yard cuts are marked with dashed lines for easy reference. The other side is designed to use with the Creative Grids Stripology series of rulers. Line up the fabric and rulers on the spaced horizontal half inch grid lines. That is all you need -- no other distracting markings and lines are needed!