I've tried to puzzle that one out myself on piano keys. I have never been able to figure out how to stitch in the ditch on each seam line without backtracking (which I hate) or leaving a small section not stitched. You can run your sloppy stitching between keys out on the edge you cut off But you end up with the section along the inside border not quilted on every other key. I was certainly not going to SITD individually and have to bury all those thread ends. I gave up and put a long loop in the center of each key instead. Good luck.