Punch with Judy > Omnigrid 96L Half Square Triangle Ruler 8 Punch Omnigrid 6" Right Triangle Ruler, Half Square Triangle Quilter's Ruler Omnigrid Mini Square Ruler Set Omnigrid #OGR2465 Fat Quarter Shop Omnigrid 8" Quarter Square Triangle Ruler Omnigrid #R98 Fat Quarter Omnigrid Quick Triangle cm Scale For 1 4 squares, up to 20 cm Omnigrid Square Ruler Value Pack Set of 4 BLICK Art Materials. The "quick triangle" is particularly popular for patchwork using fabric remnants Squares can be cut quickly and easily from fabric strips into two or four triangles without complicated calculation and in the process the seam allowances are taken into account. The transparent, resilient plastic ruler with its black and yellow grid markings and a choice of a metric or imperial scale make it possible to mark both dark and light fabrics accurately. The grid is marked in 0. 25 cm intervals, offering even greater precision.