A You Tube video recommended this ruler for the person who doesn't want to waste time calculating HOW MANY and WHAT SIZE scallops to use on a quilt or pillow sham,. I wasted a lot of time trying to figure this out BEFORE seeing the video. I was able to mark, sew and cut the scallops for two queen-size quilted shams in half a day at the most. WONDERFUL product! Now I won't even HESITATE looking at scallop-edged projects again! Thanks so much, Eleanor Burns, for creating this "MIRACLE RULER" for one very busy commercial quilter!