yep, sew just "inside" the line, marked or folded line. toward the corner of the block, not your center. just a "hair" inside will do the trick. sometimes mine all don't fold over perfectly. that's when I use the fabric square itself to measure against when sewing the 1/4 inch seam line as I connect them to others. meaning not cutting that off! you know that is square! Good luck and have fun.