I have a scant quarter inch on the edge of a piece of cardboard. It is marked with 1/4" painter's tape which in reality is actually .23 instead of .25 (which would be exactly 1/4"). So for a scant quarter the .23 painter's tape is perfect for the scant measurement. I keep this piece of cardboard handy and when I go from one machine to the next machine, I use this to make sure the needle is coming down exactly on the edge of the tape and the other edge is marked on the bed of each machine exactly where the edge of the fabric should be. I have several machines and two of them always go back to a standard setting from the company which doesn't always mean a scant 1/4". It works for me.