Lapped Zips were a hot topic on this weeks episode of The Great British Sewing Bee. I know them mainly as a Vintage technique, and my Vintage Sewing Books are stuffed full of ways to work them!
The following Tutorial is taken from McCall’s Complete Book of Dressmaking (which is delightful!). The important thing to remember when inserting Lapped Zips is to baste/tack at every stage. If rushed, the fabric can slip so that the Zip is exposed, or wrinkles. For the beautiful finish Heather achieved, remember to finish the final step by hand. This will hide the zip beautifully.
Make sure that the Placket/zip opening is 1.5cm or 5/8″ longer (not counting the seam allowance at the top if inserting in a Skirt), than the length of the Zipper teeth.
Pin back both edges of the seam 1.5cm or 5/8″ (which should be the seam allowance in the pattern), tack/baste the seam in position and press.
Place the Zip with the stopper just below the point of the opening. Pin as illustrated.
Working with the seam edge of the back, put the folded edge right up to the teeth. Tack/baste and stitch close to the metal using the Zipper Foot on the Sewing Machine. You may need to slide the tab of the Zip down to stitch past it.
Close the Zip, and place the other seam fold over it so that the metal is hidden. Even swing it over a little more so that it laps over .5cm or 1/8″ at the top. Tack/Baste the open the Zip and start stitching down from the top by hand.
From the back, push the needle through the fabric and then, a couple of threads away push it back through the fabric. The smaller the stitch back to the other side, the neater and more beautiful the finished Zip.
And there you have it, happy stitching!