Zippers are available in numerous different lengths. However, these are not always the exact ideal length that you want to make or for whatever you want to sew. It is very rare for the ready-made garments to have the similar sized zipper that will match that one available for home sewing. Good thing that it is not a very difficult task to shorten a zipper.
When you speak of shortening a zipper, it doesn’t mean that zipper teeth will poke into your garments or skin. Always purchase a zipper from ZipperShipper.com that is longer than what you need if ever the right length is unavailable. Measure the spot where you plan to insert the new zipper into.
Start by measuring and bar tacking the zipper. You can transfer this measurement on the zipper then put a mark on the zipper tape for the exact length you need. The mark is where you will be sewing over a bar tack.
The bar tack is being sewn through setting the stitch width in a way that is wide enough so that the needle will land on the zipper teeth’s two sides and set the stitch length for the stitches to be almost right above each other.
Cut the zipper under the bar tack and leave ¾ to 1 inch of the zipper. Snip off the teeth with care from the zipper tape and leave intact as much of the zipper tape as possible.
Put a ribbon or scrap of fabric or bias tape on the back portion of the zipper below where the teeth were removed. The backing tracking is going to provide a smooth surface for the zipper tape to stay intact while protecting your skin.
Zigzag over the backing material and zipper tape’s edges, keeping the zipper tape’s edges even, flat, and smooth with the width of the original zipper tape. Zigzag the zipper tape’s raw end to avoid fraying.
You can now sew in the new zipper in the normal way you do.