This 90 degree triangle cuts quarter triangles up to a finished size of 8 inches. Since the tip is trimmed, all squares and triangles can be cut from the same strip of fabric. Sew four together to create quarter-square triangles up to a finished size of 16 inches. A 1/4 inch dashed line is printed on each side of the center vertical line so you can cut 45 degree triangles that include the seam allowance. A dashed 1/4 inch seam allowance is printed around the entire edge of the ruler. The ruler slides easily over the fabric until pressure is applied. Then, our exclusive gripper holds the fabric in place while cutting, eliminating slipping and miss-cuts! The ruler comes with fully illustrated step by step instructions or scan the QR Code printed on the ruler to view a video demonstration of these features.