Olfa Frosted Advantage Non-Slip Ruler "The Workhorse"-16-1/2"X16/1/2". OLFA-Workhorse Acrylic Ruler; 16-1/2x16-1/2 Squared Non-Slip Frosted Advantage. The Workhorse is a must have in any crafting room! This ruler handles larger blocks and scrapbook album pages. Great for squaring pieced blocks borders and is used as a pillow template or for square designs. The Frosted Acrylic features easy-to-read black numbers and lines for clarity on light and dark colored materials; 1 inch grids with 1/8 inch increments ensure precise measurements.