A 5" square quilting ruler/tool for cutting and viewing your fabric scraps with an artist's eye to cancel out color and focus on value! Hold the ruler up to your eyes and look at a stack of fabric scraps through; it will cancel out the fabric's colors, allowing you to view only the light or dark color values. Trim and square up 5" pieced units to easily combine them with charm packs in your quilts. 'Ruby Ruler' by Wise Craft.