Perfect shapes and sizes, laser cut accuracy, specific-size pieces. No guessing which line to use on a ruler. Perfect quarter-inch (6mm) seam allowances already added. Perfect corners, not just blunt, but revolutionary double-blunt corners engineered for perfect alignment. Perfect for rotary cutters, cut multiple layers at one time. Perfect for hand or machine piecers. One multi-size ruler offers a no-math solution for cutting both the corner triangles and the larger setting triangles that are needed when patchwork blocks are set on point.