This OLFA rotary mat does more than just protect your work surface. It also extends the life of your rotary blades. Use the marked side of the mat for precision cutting, the solid side for general cutting. You ll notice that the gridlines include angle markings; this makes tricky tasks, like creating true bias strips, much easier. Vary the location of your cutting to allow the mat to self-heal. Particles stuck in the mat? No problem — just erase over them with an art gum eraser. The mat is great for quilting, sewing, cutting out patterns, rotary cutting, general crafting, scrapbooking and more.