perfect zippers, part 2: perfect corners

The last thing you want after you’ve installed a perfect zipper in a bag or pouch is to botch sewing the thing together!

zip pouches without dented corners

Good news, friends! It’s super easy to make sure the sides of your zip pouches and handbags don’t collapse in on themselves.

But first: let’s chat about cutting your fabric correctly. There’s no way you can sew an accurate seam if you have not cut the fabric accurately. So how do you make sure to cut the fabric just right for a zip pouch or handbag?

no need to shorten your zips

step one: cut fabric to size
I like to make my bags and pouches the exact same size as my zippers. If you sew them up right, the corners look very neat.

I don’t like to shorten zippers if I don’t have to, and I also don’t like making little zipper stops out of fabric, or (ugh) letting the zipper hang over the edge of the bag…I know that is a very common application, but it’s always been a pet peeve of mine.


zippers inserted into fabric pouches

These little pouches are made with 4″ zippers, perfect for a change purse just wide enough to fit your ID and a credit card. When I cut the fabric for a pouch this size, I cut it 5″ wide – enough for a 3/8″ seam allowance plus 1/8″ clearance on each side of the 4″ zipper.

Cutting the fabric accurately means you don’t have to worry about hitting the zipper stops with your needle!


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pin seam allowances towards the self


step two: pin seam allowances towards the self
The big secret to avoiding dented corners is to pin the seam allowances properly, before you stitch the whole bag together. You must pin and stitch the seam allowances towards the self (the outside fabric), not the lining (the inside fabric).

The “self” is the outside fabric, or the main fabric of your project.

In the image above, the gray fabric is the lining, and the white is the interfacing on the wrong side of the self.

You can see how the pin is holding both seam allowances and the zipper tape in the direction of the self.

close up of seam allowances in the correct position

Here’s a close up of the seam allowances, without the pin in the way.

When you pin, you’ll want to make sure the folded edges of the self fabric are meeting, as well as making sure the lining seam allowances are also pinned towards the self. That’s it! That is the big secret!

step three: stitch it up
Using the seam allowance you determined when you cut the fabric (3/8″ in this case), sew your bag together, with right sides facing. I always double stitch the seams on a bag, especially anything with heavyweight fabric, or many layers of interfacing.

Make sure to leave an opening in the lining, and backstitch at the beginning and end of this opening. Backstitch over both ends of the zipper as well.

Since you were super careful to position your zipper and account for the seam allowance plus clearance when you cut the fabric, you don’t have to worry about your needle hitting the zipper stop!


stitch all the way to the edge

step four: reinforce the corners
In my zeal to make the sample zip pouches for this tutorial, I completely forgot to square off the bottoms. My brain defaults to making bags with curvy bottoms, so I can’t use my little 4″ pouches to show you how to sew up the non-zippered corners right!

Above is a tablet cover in progress. When you sew a corner like this, make sure your stitches go all the way to the raw edge in both directions. Backstitch in both directions, so that where the stitches cross is super strong.


trim seam allowances at the corner to form a point

step five: trim seam allowances strategically
The most accurate cutting, the most beautiful seams, and even the most careful pressing in the world won’t matter a single bit if you don’t trim away the seam allowances properly.

Although sewing is in many ways like magical alchemy, we must still obey the laws of physics. Seam allowances are bulky and in the way, and make perfectly flat corners impossible; so we have to chop them off.

Corners at a right angle (like the one above) must be cut down to form a point.


trim close to the stitching at the ends of the zipper

The seam allowances next to the zipper ends must be trimmed very closely to the stitching (this is why you backstitch over those areas carefully).

Seam allowances on a curve must be clipped or notched, or cut off completely. On these little pouches, I cut them off all the way around (except for the opening in the lining – leaving the seam allowance intact at that spot makes closing the hole easier).

seam allowance trimmed all the way around

Once you trim, turn the bag right side out! Before you close up the lining, put your hand inside the bag and use your fingers to carefully push the seams outwards. Don’t be afraid to be a little rough with it! If you need to, use something like a chopstick or crochet hook to poke the ends of the zipper outwards.

More than half of sewing is forcing the fabric to do your bidding! This is no different. Use your fingers to coax the seams open and force them to lie flat. You may find you need to snip some seam allowances a bit more, and that’s okay!

Once you’ve got the seams looking the way you like, press the bag carefully and close up the lining.

zip pouches with flat corners

Finito! You could say that success here is all about respecting the seam allowances: measuring them properly, pinning and stitching them down in the right direction, and then strategically trimming away the excess.

Next up in the perfect zippers series: how to make fabric tabs for the ends of your zipper. I have a few more tutorials planned for the series, but comment below to tell me what types of zipper woes you’ve had, and I’ll help you fix them!

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Check out the other tutorials in the series:



65 thoughts on “perfect zippers, part 2: perfect corners

  1. I realize that this post is very old, but I just have to thank you for stating the correct way to press a sewn in zipper! Most tutorials say to press toward the exterior, which gives (at least me) terrible bumpy corners. You are only the second person to state that the zipper tape only should go with the exterior, and the teeth toward the lining. Makes such a difference! I remember it as “eating at restaurants is expensive, so we like to eat (teeth) in (lining).” Works just so much better!

  2. I’ve been suffering with dented sides on my zipper pouches to no avail. I’m going to follow your tutorial to see if I can improve. Thank you for sharing. 🙂

  3. Thank you so much for sharing this tutorial. I just finished my professional looking (no raw edges showing) zippered pouch thanks to this tutorial!! I’m excited!!!

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