CUTTING EDGE frosted square ruler is made for rotary cutting, squaring blocks, and trimming quilt pieces with clear visibility. The 16.5 in (41.9 cm) square includes a diamond carbide sharpening edge plus a frosted, non-skid surface to help keep fabric and ruler aligned. Cut with a rotary cutter along the printed grid, then store flat and avoid heat to help protect the acrylic for long-term use, for reliable results on everyday projects.