How to Add a Zipper to a Bias Cut Seam

Today I’m going to show you how to add a zipper to a bias cut seam. If you’ve ever been one who has made a bias cut garment and then inserted a pristine looking zipper and from there, tried on your garment to view your fine work, you may have nearly burst into tears by the bubbling that can occur from a zipper applied into a bias cut seam. It can look like you’re growing spines or a tail! And it can strike the fear into anyone from doing it again. It can happen in something as simple as a circle or a-line skirt, so I’m here to show you a method to get rid of the madness.

Bias Zipper Tutorial

This zipper insertion technique can be applied to all different types of zipper insertion applications, whether it be a centered application, lapped or even invisible application. Please be aware that like any zipper application, it can take time and practice – just be patient with your first try. Let’s get started!
First let’s talk about the wheres, whys and what nots. First, ripply zippers in bias cut garments tend to happen more in garments that are cut in cloth that’s drapey, like wool gabardine, crepe, 4-ply silk, silk charmeuse, etc. Drape is the key. We all want that drape and we all want that bias cut to hug our curves the way a good bias cut garment does. So if you consider that idea for a moment, the solution for a zipper in a bias cut garment is simple – we have to drape it into the garment. Crazy right? Here I’ll show you the easiest method and from there you can take the reins and try it out on other zipper applications. Note that this type of a zipper application can work even in situations where you don’t have a bias seam. Perhaps you have really curvy hips and notice that your zipper always makes you look like you’re growing an added, unwanted appendage- try this technique!
The easiest zipper application to try first when draping in a zipper is a centered application. You will need:
– a garment to put a zipper in
– a traditional style zipper
– thread
– hand sewing needle
– zipper foot
– dress form or tailor’s ham

Prep Your Zipper Opening
Step 1 – Prep your zipper opening. I believe that all zipper openings benefit from a little stabilization and especially bias cut ones. I use 1 1/4″ knit stay tape (magical stuff really) which you can purchase here (link: You can also use strips of silk organza or fusible tricot. You’ll apply this to the wrong side of each side of your zipper opening – have it extend an inch or two beyond the zipper opening. From here stitch the seam below the zipper opening.
Press Your Seam Allowance
Step 2 – Press your seam allowance open and continue on, pressing your zipper opening seam allowances open.
Drape Your Garment
Step 3 – Drape your garment on your dress form or over a tailor’s ham. The key here is that you are trying to mimmick the curve of the body as close as possible. I’ve draped a circle skirt, with a side seam zipper, here on my dress form. You’ll have to pin it onto the dress form and be sure to pin it to the place on your body closest to where you’ll wear the actual garment (the waist on my project here). In addition, make sure that the garment isn’t pulling or distorting in any place – use as many pins as you need.
Pin Your Zipper in Place
Step 4 – Pin your zipper in place. This will take some finagling. I start at the top of the zipper opening and then just keep repositioning until I’ve got something that I want.
Step 5 – Take your garment off the dress form and temporarily hand baste the zipper in place, removing your pins one at a time. Hand basting really ensures that your zipper retains the shape that was draped on the dress form, so this step is important.
Check for Ripples
Step 6 – Once your hand basting is in place, its a good idea to either drape the garment back on the dress form or even try it on, making sure that no ripples or distortions are occurring.
Stich In Place
Step 7 – Stitch your zipper in place permanently. I usually do this part by machine, but it can also be done by hand, your choice, whichever method that gives you the most control. When doing this by machine, I have my zipper open and I use the seam allowance width marker on my machine as a guide to ensure that my zipper stitching is nice and even.

Remove Hand Basting
Step 8 – Remove your hand basting and then sit back and oogle over your handy work. Trying it on and falling all over yourself about your beautifully inserted zipper in a bias cut seam wouldn’t be a bad idea either.
Continue On!
A Shaped Zipper

From there, you’ll continue on with your garment as per usual. No too bad right? This method is a little more involved than say your usual zipper insertion, but it truly provides great results with zippers in bias cut seams. As you can see here, the zipper actually is shaped to the natural curve of the body – the zipper is molded in such a way that it actually mimmicks the curve of my hip. No ripples or unusual contortions or distortions. Worry free from unwanted rippling or crazy looking appendages!

Have you ever had trouble with inserting a zipper into a bias cut garment? Ever draped a zipper into a garment before? Enjoy friends!

In case you missed it, catch Craftsy’s previous sewing Fix-It Friday about fixing shifty shoulder pads. And be sure to check in on the Craftsy blog for more tips from a sewist next Friday.

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