|Besides the conventional use of getting pockets curves, this 2 piece notion is the perfect template for sewing those pesky curve pairs anywhere. You know, like on lapels, collar, or center front hem edges. Wherever you need to sew a pair of matching curves . As Margaret Islander says, you want them to look like twins, not distant cousins.
Simply choose the curve that looks most like your stitching line and trace both curves and sew on the traced marks. I've been using gel pens alot for this kind of thing thanks to Gigi's gelpen tip. I can get a really fine line.