My friend has advised that the 1/4 inch be marked based on a ruler. It has proven to be very good advise. I use several layers cut from a roll of painter's blue tape (easy release)to mark the 1/4 in the same manner on any machine. Position the needle on the scant 1/4 spot on a ruler which now has a little hole after doing it so many times. Then with the ruler in place and square to the machine the tape piece is layed along side the ruler to make a ridge and seam guide that measures exactly the same every time. Since I often have several quilts in process and also use two machines depending on whether I am sewing in our camper, at home, or at LQS. All the blocksfor each quilt fit when I am finished because the seam is always the same "scant" 1/4in.