Learn how to sew a lapped zipper! Did you know that the zipper, the fastener that revolutionized sewing, has its own special day? Yes, the 29th of April is known as Zipper Day! Originally called the Automatic Continuous Clothing Closure, it has evolved into a simple zip or zipper. The lapped zipper does an amazing job of closing an opening on many different items of clothing and soft furnishings.
How to Sew a Lapped Zipper
Learning how to insert a lapped zipper is a necessity for those placed down the back of a dress or on the side of a skirt. The zipper at the side of a skirt will look less obvious if it is sewn as a lapped zipper. It is called this name because one side of the zip opening acts like a flap and covers the other. This creates an almost invisible closure. This opening and the way the zipper is inserted gives it the name of a lapped zipper, but the zipper itself is just an ordinary type of zipper like every other zipper used to close openings.
Here are the steps to take when learning how to sew a lapped zipper.
Step 1 - Zipper Choice
Check you have a zipper the right length and color to match the opening. Have the right color cotton and use a zipper foot. If your zipper is too long you can cut it, but make sure you either replace the metal stopper or sew a stop bar in its place. Learn how to shorten zippers.
Step 2 - Marking
Check the side of the garment that will be the front and mark it clearly with some tailor’s chalk. This side will be the side of the flap the will conceal the zipper.
Step 3 - Stitch and Baste
Mark your seam up to the point where the zipper will be inserted. Make sure you leave enough space at the top to add a waistband or any other seam allowance. Your seam allowance needs to be at least ⅝" (15mm) so increase it if necessary. I find seam allowances of ¾" (2cm) to be the easiest to work with when inserting lapped zippers.
Sew the seam, stopping at the zipper opening. Make sure you secure the seam at the bottom with a few extra back stitches because this part of the opening will take the most strain as the zipper opens and closes.
Baste the rest of the opening where the zipper will be placed with your longest stitch (normally 4.0). You can see it as the red thread in my photo.
Step 4 - Sew Zipper First Side
Press open the seam allowance.
Separate the seam allowance for the back of the garment.
Place the opened zipper on the seam allowance with the right sides together (the zipper will be facing down). The teeth of the zipper should be just to the side of the seam.
Using your zipper foot, baste the zipper to the seam allowance. You will be sewing ⅜-1/4" from the zipper teeth.
Fold back the zipper and topstitch along the edge. You should use a matching thread color for an invisible finish.
Step 5 - Place the Zipper Second Side
Check the zipper can open and close easily. Now you are left with the other side of the seam allowance.
Do up the zipper and place it over the other side of the seam allowance. Baste or pin this side and press firmly to flatten the edges before you sew.
Step 6 - Stitch on the Outside
Turn the garment to the right side.
Start at the top of the zipper opening and sew straight down this side of the zip using your zipper foot. Allow the fabric on this side to act like a flap that will cover the zipper’s teeth.
The width of this side must not be wider than the zipper tape underneath because the machine stitch must secure the side of the zipper flap and the edge of the zipper tape.
Make sure you mark with a pin or your tailor’s chalk the exact spot where the zipper ends beyond the metal. When you reach this point leave the machine needle in the fabric and lift the zipper foot. (Careful of any metal underneath as you don't want to break a needle.)
Turn ready to sew a bar across the bottom. The bar may be a slanted or a straight short bar to end the zipper opening.
Step 7 - Remove the Basting Stitches
Now you have sewn the complete zipper into the side seam and have made a flap to cover the opening using the fabric in the seam allowance. Remove the basting with a seam ripper and give the zipper opening another press.
How to Sew a Lapped Zipper - In Conclusion
The zipper should open and close with ease and the flap part should point towards the back of the garment. The rest of the finish depends on the item you have made. A skirt will need a waistband while a dress may have had the zipper sewn in the side to help get the dress on and off easily. If the lapped zipper is in a cushion, it is best to sew the seam with the zipper first and complete the cushion and the other seams after the zipper opening is done.
You may find once you have tried this lapped zipper you will have other uses for it because it can neatly conceal the teeth of the zipper - little bags, purses, and pouches all need a neat zippy closure. Try the lapped zipper closure and you will be amazed at how useful it is.