Sew perfect 1/4in seams! The smooth surface reduces resistance and allows easy machine quilting. Save time with Sew Straight by sewing unmarked diagonal lines and Triangle Squares. There are countless ways to use Sew Straight. Accurately sew bias seams for Binding in a jiffy. Quickly check patch size with reference lines. Self-Adhesive Backing that can be removed and repositioned over and over. This is not a cutting mat.