The Omnigrid 1in x 6in ruler is used when sewing and quilting to check seam allowances, trim foundation piecing, and mark hems and seam allowances. Use with a rotary cutter or a straight-edge blade. Edge markings for accurate measuring. Laser cut edges for smooth, deep cutting. Patented double-sight lines that show up on light and dark fabrics. Heavy-duty durable acrylic material. Left- and right-hand use.