Use this set of 3 rulers to quickly and accurately perform a variety of marking tasks. The center line is exactly 1⁄4″ from both edges of the ruler. This provides an accurate reference line for: marking 1⁄4″ sewing lines, adding 1⁄4″ seam allowances, checking 1⁄4″ seam allowances and marking 1⁄4″ quilting lines. Made of strong and durable premium quality acrylic plastic. Black markings. Laser cut to within 0.002″ accuracy with a smooth finish. Specially designed for right and left handed use. CAUTION: Do not use rulers with rotary cutters - knives or other cutting instruments. Rulers are designed for marking use only. Injury may result if rulers are used for cutting and trimming tasks.