What Jan said, and try drawing that line on a sheet of fine sandpaper...grabs the fab so it doesn't move. If you are having that much trouble sewing on or 1/4" from that drawn line, perhaps you should try either using triangles on a roll, thangles or even use the right angle HST template and cut the triangle first then with the bladed 1/4" foot sew that seam. Remember there are several ways to do one thing...find the one that works best for you...