The Omnigrid Marking Trio contains 3 rulers that can be used to quickly and accurately mark stitching lines. Rulers are 1/2" x 4", 6", and 12". Perfect for marking pre-cuts to make half-square triangles. Double-sight line is printed down the middle of each ruler providing visibility on light and dark fabric. 1/8" thick optical-acrylic is laser cut for a smooth edge and accuracy. Item Number: R1264S 1/8" ruler markings along edge of ruler for measurement and placement accuracy Patented double-sight lines for visiblity on light and dark fabrics Do not use with rotary cutters, knives, or other cutting instruments 4", 6", and 12" rulers included in set Optical-grade acrylic with smooth, laser cut edges Use a pencil with a fine, sharp point for the most accurate mark