The Cutting Edge Sharpening Edge Ruler 6-1/2in SquareThe Cutting EDGE Quilting Rulers feature a patented design with a diamond carbide edge that sharpens rotary blades with every cut. These revolutionary rulers come in 17 popular styles and offer easy to read numbers, square up guides, and diagonal dots that make lining up cuts quick and accurate. The fully frosted backing gives you the right amount of steadiness for cutting, but also allows you to slide the rulers when needed. The red lines are