This 18 1/2" square features easy-to-read black and white markings printed in 1" grids marked in 1/8" and 1/4" increments. Use the easy-to-read, numerical black numbers (printed on white dots) and the 1/4" grip sides to cut whole inches. These 1/4" grip sides accentuate the dashed lines printed 1/4" away from two adjoining edges to aid in trimming seam allowances. Use the patented Turn-A-Round feature designated by the easy to read, numerical white numbers (printed on black dots) and the 1/2" grip sides to add the 1/2" seam allowance. Our exclusive gripper holds the fabric while cutting when pressure is applied. A 45° angle is printed in black. White horizontal and vertical lines are printed on the square so the center of the ruler is easily distinguishable.