OLFA Frosted Advantage 16.5x16.5 Inches Square Acrylic Ruler is non- slip for stable and safe cutting. Frosted back with black grid lines for clarity on light- and dark-material. The large bold black numbers are easy to read. The rulers have black grid lines at every inch; dotted black lines mark the half-inch and black tick marks along the solid line mark the quarters and eights. The frosted back grips in place for safe; stable cutting but allows the ruler to be repositioned for small adjustments. USES: The 16.5x16.5 inches is great for squaring larger pieced blocks; cutting larger pieces and works well as a template for pillow tops and simple square patchwork designs. Also great for fashioning scrapbook and album pages. For right-and left-handed use. Hole for convenient hanging. Available in 10 sizes. Imported.