The concave and convex sides of this ruler are the same so both sides can be used so crosshatching and continuous curve can be done without crossing the hands. Mark a line at the angle you are going to stitch your arcs. Line up the middle line of the ruler with your drawn line and stitch. Match your stitching line to a curved measured line on the ruler to make your next curve, be sure to match the center line with each stitching.
These rulers are cut in our 1/8" sea-foam colored plastic for domestic machines. If there is a size you would see made available, let us know.