How to sew an invisible zipper is a skill with which many sewists struggle.
Concealed zippers are sewn in sort of “backward” but end up facing forward. This often leads to:
- Twisted zippers
- Zippers sewn on the left when they should be on the right
- Zippers sewn on the inside when they should be sewn on the outside
And, let’s not even start about the failure to sew close to the zipper coil, which makes an invisible zipper visible to anyone looking at the seam.
Argh, rage building!
In this invisible zipper tutorial, you will discover how to avoid these issues. Follow the photographed step-by-step instructions and tips on how to sew an invisible zipper.
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The Many Ways to Sew a Hidden Zipper
Darlings, I wanted to dive deeeep into instructions on how to sew an invisible zipper, so I could bring you advice that you’ve never heard before.
To this end, I turned to my collection of sewing books.
Because the first place you go for information is the internet, yes?
So, if I go to books — especially some unexpected titles — there’s a good chance I’ll bring you something you’ve never/rarely seen on the ole’ interwebs.
The following books informed this article:
- “The Dressmaker’s Technique Bible” by Lorna Knight
- “High-Fashion Sewing Secrets from the World’s Best Designers” by Claire B. Shaeffer
- “Power Sewing Step-by-Step” by Sandra Betzina
- “Reader’s Digest Complete Guide to Sewing” published by The Reader’s Digest Association, Inc. (© 1976)
- “Sew… The Garment-Making Book of Knowledge” by Barbara Emodi
- “Sewing Secrets from the Fashion Industry” edited by Susan Huxley
Would you believe that every book had a slightly different approach to sewing an invisible zipper?
I found that incredibly wild.
What’s more, it makes sense if you haven’t found an invisible zipper tutorial that’s worked for you yet. There are many ways to install these skinny buggers.
Anyhoo, the method in this article pulls on information I gathered from each tome, especially when it comes to ✅ TIPS.
RELATED: Favorite Sewing Books: Lurk My Library
Step 1: Interface the Seam Allowance
Apply fusible interfacing to the wrong side of the seam allowance where the zipper will be inserted. The IF should be as long as the zipper and as wide as the seam allowance.
Interfacing gives the fabric more robustness to support the zipper.
Interfacing is especially important if you’re using a lightweight or slinky fabric. You may want to pink the edges of interfacing if you’re using it on lightweight fabric; pinking makes the IF invisible from the right side of the fabric.
✅ TIP: You can give the zippered seam even more backbone by making the IF a little bit wider than the seam allowance. That way the interfacing will sit under the seam.
Step 2: Examine the Zipper
Check out the closed invisible zipper. If the zipper is wavy or lumpy, give the tape a press with low heat and a press cloth, as most zippers are made of synthetic materials.
Packaged zippers get folds and kinks that are best flattened before installation.
Don’t open the zipper to press it, and don’t press the coil.
✅ TIP: According to Claire Shaeffer, “To avoid having skirts look homemade, use only zippers that are 8 inches long or shorter, unless you are extremely tall.”
✅ TIP: If the invisible zipper doesn’t match the garment, have no fear. The zipper tape and coil will be invisible once installed, and you can paint the zipper pull with nail polish that coordinates with the garment.
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Step 3: Finish the Raw Edges
Finish the raw edges of the pattern pieces where the invisible zip is being installed.
Pinking, serging, zig-zag stitch, etc. — choose your choice.
Skip this step if the garment will be lined.
Step 4: Make Your Mark
Make marks in four key places:
1.) On the right sides of the fabric, draw the seamline where the zipper will be installed.
The seam allowance line should start from the (top) raw edge of the fabric and finish at least a few inches longer than the zipper.
2.) On the right sides of the fabric, also mark the top (intersecting) seamline (e.g., waist seam, neckline seam, etc.)
3.) Just below the top seamline, mark the location for the top of the zipper coils (where the slider will sit when the zipper is closed).
➡️ If there’s no hook above the zipper, the top of the coils should sit 0.125 inches (0.3 cm) below the seamline.
➡️ If there is a hook, the top of the coils should sit 0.375 inches (1 cm) below the seamline.
The location for the top of the zipper coils must be the same on both fabric pattern pieces.
4.) Close the zipper and turn it to the wrong side. Make a mark above the top of the coils.
RELATED: How to Sew an Exposed Slot Zipper
Step 5: Place the Zipper
Place the left and right pattern pieces right sides up on the work surface. (The right sides are marked with the seamline, top seamline, and top of the zipper coils.)
Set the closed zipper face down (wrong side up) on the seamline.
(It doesn’t matter whether you set the zipper on the left or right pattern piece; see below: “✅ TIP: Don’t Worry About Sides When Installing an Invisible Zipper.)
The coil should sit exactly atop the seamline; the overdrawn seamline makes it easy to see if the coil is aligned.
Align the top coil mark on the zipper with the top coil mark on the fabric.
One side of the zipper tape will be in the seam allowance, and one side will be on the right side (face) of the garment. This is the starting point for the next step.
✅ TIP: Don’t Worry About Sides When Installing an Invisible Zipper
A word about right sides and left sides of the zipper and the fabric: Don’t worry about it.
When you start talking lefts and rights — and then you mix in right (face/outside/exterior)) side of fabric and wrong (inside/interior)) side of fabric — it’s a recipe for confusion.
Instead, try this.
1.) Fold over the fabric seam allowances and give them a finger press.
2.) Butt the folds against each other as they would be in the garment.
3.) Slide the closed invisible zipper, right side up, behind the “seam.”
4.) On one side (doesn’t matter which — pick one), peel the fabric seam allowance away from the zipper.
5.) The revealed side of the zipper and the revealed seam allowance are a matched set. Give the seam allowance and zipper tape an indicator to show that they belong together — chalk mark, tailor’s tack, safety pin, sticker, etc.
Now you have two matched sets — unmarked and marked. And this will help you immensely when walking through zipper installation.
Whenever you feel turned around, remember that like goes with like.
Step 6: Sew the Zipper to the Seam Allowance
What’s smart about sewing the zipper to the seam allowance is if you need to rip the stitches near the coil (which happens frequently), you don’t have to resew the whole zipper.
The zip is held in place by the stitches in the seam allowance.
Also, when you sew the concealed zip to the seam allowance, it rests flat in the garment, particularly at its end, making the garment more comfortable to wear and looking smoother from the outside.
When sewing to the seam allowance:
- Start at the top of the zipper tape.
- Use an average stitch length (2.5-3.0 mm).
- Use a regular zipper or standard presser foot. I found a standard presser foot gave me the best pressure on the zipper tape and fabric as they moved under the needle.
- Backstitch at the beginning and end.
- Sew on the edge of the zipper tape to keep from crowding the (future) stitches near the coil. You may need to adjust needle position to put the stitching close to the edge.
✅ TIP: When you adjust needle position, test it first by slowly lowering the needle with the flywheel. It’s all-too-easy to move the needle to a position where it will strike the presser foot.
I suggest two ways to hold the zip in place while you stitch its tape to the seam allowance:
1.) Pins
Start with the zipper closed and right side down.
Pin one side of the zipper tape to the seam allowance, making sure the pinheads face your body (so you pull out the pins in the direction of the stitching).
Open the zipper. Sew tape to the seam allowance.
Close the zipper. Realign the zipper coil and seamline. Pin the other side of the zipper tape to the other seam allowance.
Open the zipper. Sew tape to the seam allowance.
2.) Wonder Tape (Wash-Away Double-Sided Basting Tape)
(Note: I used Wonder Tape in the photos.)
Put strips of Wonder Tape on the right side of the zipper tape. Don’t remove the paper yet.
Place the closed zipper coil right side down on the seamline, aligning the top coil marks.
While holding the zipper in place, peel the Wonder Tape paper from the side of the zipper tape that’s on the seam allowance. (Readjust the zipper’s position as necessary.)
Let the Wonder Tape do its thing; stick the zipper tape in place on the seam allowance.
Open the zipper. Sew tape to the seam allowance.
Close the zipper. Realign the zipper coil and seamline.
Peel off the Wonder Tape paper on the other zipper tape. Stick the other side of the zipper tape to the other seam allowance.
Open the zipper. Sew tape to the seam allowance.
Step 7: Press the Zipper Teeth
Open the zipper after it’s sewn to the seam allowances.
Using low heat and a press cloth, press the zipper teeth open. Roll each side of the coil away from the tape.
Pressing the teeth open will help the final stitching get as close to the coil as possible.
DO NOT close the zipper. If you close the zipper, you re-roll the zipper coil and undo the pressing.
Step 8: Sew Close to the Zipper Coil
You can sew the zipper with an invisible zipper foot, or you can use a regular zipper foot and move the needle so that it’s tight against the coil. I think the invisible zipper foot is easier, because it spreads the coil for you.
✅ TIP: You may spread the coil open with an awl.
Regardless of the presser foot you use, try your hardest to avoid hitting the coil and especially avoid sewing over it, because if you sew over it, the zipper slider can’t pass over that spot. Plus, you’re more at risk of breaking a needle.
Start with an open zipper. Take one side of the zipper, and place it wrong side up (fabric right side up).
Do not fold the seam allowance; keep the SA flat. You’re sewing through the wrong side of the zipper tape (next to the coil) and right side of the seam allowance (on the seamline).
Lower the needle into the zipper tape, as close as possible to the top of the zipper coil. Then lower the presser foot. Secure stitching with a backstitch.
✅ TIP: You can vary the closeness of the needle to the zipper coil (i.e., needle position) depending on the thickness of the garment fabric. For heavyweight fabrics, the needle can be close; for medium-weight fabrics, the needle can be closer; and for lightweight fabrics, the needle can be closest. Test and see.
Slowly sew one side of the coil from the top of the zipper coil (not the top of the zipper tape) to as close to the slider as you can go.
✅ TIP: To prevent puckering on thin fabrics, hold the fabric and zipper firmly in front of and behind the needle. Let the feed dogs move the layers.
You’ll notice that as you get close to the slider, the coil will start to curl in. This is when you’re most likely to sew over the coil.
Flatten/spread the coil as best you can, but it’s better to stop sewing before things really become a PITA. All presser feet stop working well when the surface stops being flat.
Leave the thread tails long. Pull the upper thread to the back (by the coil) and tie off to secure the stitching. Cut the threads extremely short so that they don’t interfere with the zipper pull.
Repeat for the other side. Make sure you stop stitching and tie off at a point equal to the other side, i.e., the lines of stitching next to the coil should be the same length.
Note: These photos might be the *slightest* bit confusing, because they show the finished zipper with a folded over seam allowance. To remind you again, the seam allowance is not folded when sewing next to the coil.
Step 9: Check the Zipper Installation
Turn the fabric and zipper right side up. Close the zipper.
The tops of the coils of the left and right zipper tape should align, and the seam should be smooth — i.e., both sides of the zipper tape should match, and the zipper should be undetectable in the seam.
The only part of the zipper you should be able to see is the pull — no zipper tape. What color is the zipper tape? No one knows, because it’s… invisible!
Now open the zipper. It *should* pull down without (excessive) force.
If you hit a spot on the coil that you can’t pass, DO NOT FORCE IT.
If you force it, there’s a high likelihood that the zipper will break. Invisible zippers can be fickle creatures.
Examine the zipper, and you’ll probably find that you stitched over the coil. Unpick the stitch and restitch.
You may only need to restitch a few stitches, so don’t go crazy with the seam ripper unless the entire zipper is less pretty than you need it to be.
Step 10: Sew the Remaining Seam
When sewing together the rest of the (unzipper-ified) seam, draw in the seamline on the wrong side of the fabric to ensure you stay straight and the correct distance from the edge.
“Fold” the closed zipper the long way to bring together the edges of the fabric pattern pieces, mostly below the zipper.
Switch to a regular zipper foot. Start the stitching 0.25-0.325 inches (0.6-1 cm) above the end of the zipper stitching. (Backstitch at the beginning, natch.) Sew from the top down to smooth out bubbles of grain.
This stitching starts parallel and a tiny bit outside the zipper stitching in the body of the garment. Within a few stitches, you should land on the drawn-in seamline.
Take care to only sew the fabric and not the zipper. Use your fingers!
Continue sewing to the end of the seam. Backstitch.
Step 11: Give a Final Press
Turn the fabric and (closed) zipper right side up.
Using a press cloth and low heat, press the seam over the zipper.
Flip the fabric and (closed) zipper to the wrong side.
Press the seam allowance open below the zipper with heat and steam appropriate for the fabric.
Turn the fabric and closed zipper back to the right side. Open and close the zipper a few times, and admire your handiwork. YOU DID IT!
Final Thoughts on How to Sew an Invisible Zipper
I hope this invisible zipper tutorial gave you an “aha!” moment that leads to a future of undetectable zippers.
When sewing concealed zippers, I have found that going the extra mile with marking seam allowances and match points makes the difference between successful invisible zipper installation and ripping out a zip at least one time.
I’d rather draw a few lines than unpick stitches any day.
Over to you: What’s YOUR top tip for how to sew an invisible zipper? Which tip in this post was totally new to you? Please leave a comment. Thanks for reading.