Mini Tutorial: How To Finish Seam Allowance Edges With Zigzag Stitching
Regardless of how simple or complex your home sewing machine is, you can always rely on a plain zigzag stitch to clean finish seam allowance edges no prevent them from fraying and adding extra stability to the seam. The beauty of a zigzag stitch is that you can adjust the density and length of the stitch to accommodate the fabric at hand. If the fabric frays heavily, use a denser stitch, if the fabric is structured and doe not fray much when cut, you can use a lower density stitch. Once the setting is adjusted based on your fabric, follow these simple steps to cleaning finish the seam allowance layers.
1. Apply the zigzag stitch at about 1/8" away from each seam edge as shown.
It is much easier to apply the zigzag to each edge individually prior to aligning and sewing the seam. While you can choose to apply the zigzag stitch directly to the fabric edge, you'll find that if you apply it within the seam allowance and then trim the excess, the edges will lay much smoother featuring a more even stitch application. However, it is important not to trim the excess prior to sewing the seam.
2. Align and pin the seam edges as you would with any conventional seam. Machine stitch the seam following the appropriate seam allowance guide on your sewing machine- the machine guide should align perfectly with the raw fabric edges ( not the zigzag stitch).The reason the excess is not trimmed until after the seam is stitch is to allow for an accurate way to apply the stitch from the correct (initial) seam allowance edge.
3. Once the seam is stitched, trim the excess fabric next to the zigzag stitch application. Be careful not to accidentally cut through the stitch as you trim.
To be on the safe side, trim the excess at about 1/16" away from the zigzag stitch- this will keep you safely out of the way of the stitch in the cutting process. Once complete, the zigzag should align directly with the seam allowance edges, providing a smooth clean finish. As always, to complete the seam, iron it with the seam allowance layers open.
Note: You can apply the zigzag finish after the seam has been stitched if the seam allowance is wide enough to allow a comfortable application. Keep all other layers out of the way as you apply the zigzag stitch to each individual seam allowance layer.