This rectangular quilting ruler features easy-to-read black and white markings printed in 1-inch grids marked in 1/8-inch and 1/4-inch increments. Use the easy-to-read numbers and 1/4-inch grip side to cut whole inches and trim seam allowances. Use the white 45-degree angle to trim half-square triangles in whole-inch increments. Use the black 45 degree angle to trim half-square triangles in half-inch increments. The ruler slides easily over the fabric until pressure is applied.