Cut accurately. The measuring line on the ruler should be ON the fabric. Place a half-inch strip cut from the sticky end of five post-it notes (2.75" square) on your machine bed. Be sure it extends from the back end of the foot forward toward the front of the machine and lays along the edge of your quarter inch foot. Test your needle position. Three 1.5" width strips sewn together should measure 3.5" across finished. Adjust the needle position after measuring the width of your test piece. Tape the sticky strip down when the position is accurate. On my machine the strip lays against the right feed dog. I ALWAYS use this strip and replace it when needed which happens frequently, because I have to remove it to get to the top-loading bobbin.