https://www.guidelines4quilting.com/products/seam-guide-setter Magnetic Seam Guide* A magnetic seam guide is not only easy to see, it won’t budge when placed on the throat plate of your sewing machine. You only need to keep the fabric edge on the necessary marking say 1/2 inch and your machine will sew the seam line with the 1/2 inch seam … 2. On most of the sewing machines, the throat plate under the needle usually has markings for the seam allowance. You can place it along any seam guideline on …