WHAT IS IT?
A lapped zipper is a type of zipper application in which one side overlaps the zipper. The zipper is positioned so that it hides under this overlap. The zipper is harder to see from the overlap side of the zipper and easier to see on the side without the overlap. Instead of a centered zipper (page link), for which the zipper is in the middle of the opening, a lapped zipper has one wide side that covers the zipper and one narrow side underneath. Lapped zippers are inserted after the seam below the zipper opening is sewn.
WHEN DO YOU USE IT?
A lapped zipper is a good type of zipper application for side zippers, because the overlap covers the zipper teeth. The lap also hides zipper teeth that are not a perfect color match. Use lapped zippers on skirts at the side seam, dresses at the side or at the center back, or blouses that have zippered openings at the top of the back neck.
Tips + Notes
- Lapped zippers can be sewn into seams with a standard 5⁄8″ (1.5cm) seam allowance, but it works even better if the left seam allowance is slightly wider. Increase the left seam allowance to at least ¾” (1.9cm) so the raw edge of the lap is easier to catch in the topstitching (page link).
- For zippers in lightweight or shifty fabric, you may want to stabilize the zipper opening with fusible interfacing (page link). Cut two 1″-wide (2.5cm) strips of interfacing the length of the zipper opening, and fuse along the zipper opening.
- Instead of topstitching the left side of the zipper, why not hand pick it? Follow the steps for hand picking a zipper on (page link) and use this technique instead of the topstitching.
HOW TO SEW A LAPPED ZIPPER
Start after the seam below the zipper has been sewn. If the zipper is going into an unlined garment, finish the seam allowances of the zipper opening all the way down to the bottom of the seam. If the zipper is going in a lined garment where the seam allowances will be enclosed, leave the seam allowances unfinished. Machine baste (page link) the zipper opening above the seam closed, and press it open.
For a side-lapped zipper, where there is a seam below and above the zipper opening, place the top zipper tape edges so they are touching without overlapping, and whipstitch (page link) the tape together at the top edge. In this sewing example, the zipper is open at the top, so I didn’t whipstitch the end, as you’ll see in step 3.
Switch to a zipper foot. From the inside of your garment, with the top of the zipper opening facing you, open up the right seam allowance. Open the zipper and place it face down on the seam allowance, with the bottom stop on the marking and the coil/teeth next to but not on top of the seam. Machine baste (page link) down the middle of the zipper tape through the tape and seam allowance only, from top to bottom.
Switch back to a regular stitch length, zip up the zipper, and form a fold in the seam allowance but not in the tape. Bring the fold close to the zipper coil but not close enough to touch, and pin it in place. Edgestitch (page link) the fold to the zipper tape, moving the slider out of the way as you sew.
Flip the garment over to the right side, and if you unzipped the zipper in the last step, zip it back up. The zipper now lies under the free seam allowance and a pleat is formed at the end of the zipper opening. Secure with pins. Hand baste (page link) across the bottom of the zipper and up the left side about 3⁄8″ (1 cm) from the seam. Make sure your hand basting is accurate, as you’ll be using it as a stitching guide in the next step.
On the outside of the garment, just outside the basting lines, begin topstitching (page link) at the bottom of the zipper, across the bottom, then pivot and sew up the side. For zippers that are going to open all the way up to the top, sew to the end of the tape. For zippers in the side seam, or any seam that is sewn at the top and bottom of the zipper opening, stitch to the top, pivot and sew toward the seam. Press the zipper opening, and remove basting stitches.
Source : The Sewtionary An A to Z Guide to 101 Sewing Techniques + Definitions
About the Author : Tasia ST. Germaine