This 8-1/2 x 18-1/2 inch rectangle ruler is a workhorse. It is the perfect size to span the most popular size of rotary cutting mats. And, since it is 25% smaller than the original 24-1/2 inch version, it is easier to manipulate. The wide width makes it the perfect choice to square up corners and borders. It features easy-to-read black and white markings printed in 1in grids marked in 1/8 and 1/4 inch increments. Use the black numbers (printed on white dots) and the 1/4 inch grip sides to cut whole inches, while the white numbers (printed on black dots) and the 1/2 inch grip sides add the 1/2 inch seam allowance. 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. An additional black 45 degree line is placed so that two angles cross 1/4 inch away from the outside edge. Use these markings to square up flying geese units; squares set on