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.