when we were working on a group quilt at our Guild, one of our more "senior" members (one who has won numerous awards by the way!!!) Worked with me to perfect my 1/4" --- turns out, a big part of the problem is a wobbly machine foot!!! I love that particular machine, but the bottom of the foot has too much "play" in it... changed to a "Litte Foot" and my problem was solved! I still use the painters tape trick, but my 1/4" is so much more accurate (Not perfect yet, but at least straight lol)