This 15-1/2" Square Ruler by Creative Grids provides everything you need for easy and accurate measuring and cutting! It features easy-to-read black and white markings printed in 1” grids and marked in ?” and ¼” increments. The diagonal line makes trimming half-square triangles easy and accurate. The ruler slides over fabric until pressure is applied. Then, its grip feature holds the fabric in place while cutting, eliminating slipping and miscuts.