Pick a ruler and tale a close look at the dividing lines. For example, between 1" and 2" count how many lines you see. If you count 8 lines then each one = 1/8" increment. In that case you would align the edge of the square with the 3rd line. IF there are only 4 divisions, then each one = 1/4". Just remember that 1/4 = 2/8 so you would need to align the fabric between the 1st and second dividing line. Hope this helps.