Jan is right. Also, it was implied with other postings, but not stated: The "scant" quarter inch means from the edge of the seam. A seam has thickness, about 2-3 weaving threads worth. you need to account for that in placing your seam. A good rule is to stop and check after the first seam. If it is not right, go back THEN and correct it. I use a paper hanger's seam roller to quick press my seams and check them.