How (and Why) to Do a Vintage-Style Lapped Side Zip

Have you ever noticed how vintage dress patterns usually have side zips instead of the back zips found in most modern patterns? A well-made vintage dress will almost always have a side lapped closure - and a metal zip, of course. I think there's something so sophisticated about a perfectly-executed side zipper. It adds that lovely authentic touch to your retro sewing projects. Here's how!

Sew the left side seam of your dress, leaving an opening for your zipper (the opening is generally 14" long). With a a side zip, your seam will be sewn about 2-3" above the zipper (below the armhole), left open for the length of the zip, and then sewn shut below it. Make sense?

You're going to create a placket, which is basically just a little facing for your left side opening (that's the side that's lapped). This makes your seam allowance a little bigger and also stabilizes the lap. Cut an on-grain strip of your fabric that's 1-1/2" wide and as long as your zipper opening. If your fabric is filmsy or soft, you will probably want to interface the strip. A bit of silk organza works well for this.

Now, pin the strip to the left side of your zipper opening, right sides together.



Stitch the strip on with your usual 5/8" seam allowance.

Here it is stitched:



Trim and grade the seam allowances. The narrower seam allowance will be the strip.

Turn the placket to the inside of the dress and press.

You might want to put in some temporary diagonal basting to keep the strip in place after turning it in.
Turn the right side seam allowance under 1/2". (NOT the full 5/8" of your seam allowance.)

Pin the zipper to the left side of the seam allowance, aligning the folded edge right next to the teeth of the zipper.
Using a zipper foot, stitch close to the folded edge, next to the teeth. Here's what your stitching will look like.

Now, keeping the zipper closed, fold the left lapped side over the right side of your zipper. Pin in place along the left side, where the lap will be stitched.

Now you can stitch the lap on your machine if you like. Use chalk to mark a line 1/2" away from the fold to maker your stitching line. Or use a foot with a gauge like this:

Or - my preferred method - you can hand pick the lapped side. I've always found stitching a lapped zipper by machine to be somewhat frustrating - the zipper tab gets in the way, and it's hard to get a straight line even with a gauged foot. With a hand-picked zipper, you get so much control that the zipper always goes in perfectly the first time.

To do this, unzip the zipper, keeping the lapped side pinned in place and pick stitch about 1/2" away from the lapped edge, as well as horizontally across the top and bottom of the lap. For a fantastic article on this method, click here.

I ended up hand-picking the Background Dress zipper:

I just adore the look of hand-picking in conjunction with a beautiful metal zip. Here's my lemon dress to refresh your memory:

Hope this all makes sense! Please leave any questions in the comments.

Update: It's easy to incorporate this into a dress that has a center back zip. You'll probably want to eliminate the center back seam by cutting the back pieces on a fold (make sure you eliminate the seam allowance first!). Then leave a 14" opening on the left side seam of your dress. Start the opening two inches down from the armhole. Insert your zipper as directed above. That's all!