OLFA, Non-Slip, Frosted Advantage™ Acrylic Rulers are not your ordinary rulers! OLFA's rulers are non-slip for stable and safe cutting and frosted with black grid lines for clarity on light- and dark-material. "The Charm" is 4" squared and is great as a template for 4" squares used in 9" patch blocks, baby quilts, miniatures, charm quilts, and paper crafting. The easy to read number and grid lines with 1" grids and 1/8" increments ensure precise measurements. For right-and left-handed use. Available in 10 sizes to accommodate all your crafting needs; no matter the project, we've got you covered.