I found a scant-quarter-inch foot for my Featherweight, and as if by magic, my flying geese have been coming out [nearly] perfect. I found it on a video from The Featherweight Shop that compared 4 different 1/4" feet, including "accurate" and "scant" sizes. The foot has a bumper on the side. Just bump the edge of the seam against it to get a perfect scant 1/4". No eyeballing, no thread-counting. Now I'm going to look for one for my bigger machine.