How to sew an invisible zipper (step by step)
To sew an invisible zipper, you press the coils flat, stitch each side of the zipper to the open seam with the coil tucked into an invisible zipper foot, and then close the seam below it. Done well, the zipper disappears into the seam and only the small pull tab shows. This guide covers how to sew an invisible zipper from start to finish, including how to line up a waist seam across it and how to fix the pucker that often appears at the bottom.
What you need
- An invisible zipper longer than the opening. The slider and bottom stop need room below the opening, so buy one 1 to 3 in (2.5 to 7.5 cm) longer than the zipper opening, or the length your pattern lists. You can shorten it afterward.
- An invisible zipper foot. It has two grooves underneath that hold the coil open so the needle can sew right next to it. Plastic universal versions fit most machines; check the shank type for yours. A regular zipper foot also works (see below).
- Lightweight fusible interfacing, cut in 3/4 in (2 cm) wide strips, to stabilize the opening in thin, loose or stretchy fabrics.
- Matching thread, pins or clips, chalk, and an iron with a pressing cloth.
Prepare the seam and the zipper
Invisible zippers go into an open seam, so do this before you sew the seam the zipper sits in.
- Check the seam allowance. Many patterns use 5/8 in (1.5 cm); some use 1/2 in (1.3 cm) or 3/8 in (1 cm). The zipper coil will sit exactly on the seamline, so you need to know where it is.
- Stabilize the opening if needed. Fuse a strip of interfacing to the wrong side of each seam allowance along the zipper opening. This stops the fabric stretching while you sew and helps prevent ripples.
- Finish the raw edges of both seam allowances with a serger or zigzag stitch while the pieces are flat.
- Mark the seamline on the right side with chalk, and mark where the zipper ends (the bottom of the opening) on both pieces.
- Press the coils flat. Open the zipper, turn it face down and, with the iron on a low or synthetic setting, gently roll each coil open with the tip of the iron so the tape lies flat next to it. Invisible zipper coils are nylon and can melt, so keep the heat low and use a pressing cloth if you’re unsure. Flat coils are what let you stitch close enough for the zipper to vanish.
How to sew an invisible zipper, step by step
Set your machine to a straight stitch about 2.5 mm long (10 to 11 stitches per inch) and attach the invisible zipper foot.
Sew the first side
- Open the zipper fully.
- Lay it face down on the right side of the left-hand piece, with the coil sitting on the seamline and the zipper tape in the seam allowance. The top stop should sit just below the top seamline: if the edge will be finished with a facing or waistband, keep the stop below that seamline so the slider doesn’t get caught in it.
- Pin or baste. On slippery fabrics such as crepe or viscose, hand-baste the tape in place, or machine-baste along the outer edge of the tape at about 4 mm.
- Stitch from the top down. Place the coil in the groove of the foot and sew until the foot hits the slider. Backstitch.
Sew the second side
- Close the zipper and lay the pieces right sides together to check the zipper isn’t twisted and the tops line up.
- Open the zipper again and pin the free side face down on the right side of the other piece, coil on the seamline.
- Mark any cross seams (see the next section) before you sew.
- Stitch from the top down with the coil in the other groove of the foot, until you reach the slider. Backstitch.
- Close the zipper and check from the right side. You should see only the pull tab. If the tape shows in one spot, unpick that section and sew it again a little closer to the coil.
Close the seam below the zipper
- Switch to a regular zipper foot, with the needle on the side nearest the zipper.
- Pull the zipper tail out of the way, away from the seam allowances.
- Pin the rest of the seam, right sides together.
- Start sewing about 1/4 in (6 mm) above the end of the zipper stitching and a hair outside it (toward the seam allowance), then sew down the rest of the seam at the normal seam allowance. The two stitching lines don’t need to meet exactly; a tiny gap is better than an overlap.
- Press the seam open below the zipper. Press the zipper area from the wrong side only, with low heat.
- Secure the zipper tail by stitching each side of the tape to its seam allowance only, not the garment, so it can’t flip around inside.
Matching a waist seam across an invisible zipper
When a zipper crosses a seam, such as the waist seam on a dress or a jumpsuit, the seam must meet exactly on both sides or the misalignment is obvious. Sewists on forums mention this more than any other invisible zipper problem.
- Sew and press the cross seam first, and trim or grade its seam allowances so they’re not bulky under the zipper.
- After stitching the first side, close the zipper and use chalk to mark where the cross seam lands on the unsewn zipper tape.
- Open the zipper and pin the second side so the mark sits exactly on the cross seam. Hand-baste across that point.
- Sew the second side, close the zipper and check before you remove the basting.
The Palma wide-leg jumpsuit closes with an invisible zipper at the center back, and its notions list calls for an 18 in (46 cm) invisible zipper. On a jumpsuit like Palma, the center-back zipper runs across the waist seam, so the matching steps above are worth taking. The neckline is finished with facings, so keep the top stop below the neckline seamline and the facing ends will fold back neatly around the zipper tape.
Common mistakes and how to fix them
| Problem | Likely cause | Fix |
|---|---|---|
| Zipper tape shows on the outside | Coils not pressed open, or stitching too far from the coil | Press the coils flat and re-stitch closer, with the coil in the foot’s groove |
| Zipper won’t close, or slider sticks | Stitching sewn over the coil | Unpick that section and sew again just beside the coil |
| Pucker or bubble at the bottom | Lower seam started too far below or across the zipper stitching | Restart the seam 1/4 in (6 mm) above the zipper stitching, just outside it |
| Waist seam doesn’t line up | Second side not matched to the first | Mark the cross seam on the tape and baste before sewing |
| Wavy or rippled opening | Fabric stretched while sewing | Fuse interfacing strips to the seam allowances and don’t pull the fabric |
| Zipper twisted inside | Second side pinned upside down | Close the zipper and check before sewing the second side |
Shortening an invisible zipper
If you can’t find the exact length, buy a longer zipper and shorten it from the bottom. Mark the new end of the opening on the zipper, sew a bar tack or several hand stitches across the coil just below that mark to make a new stop, and cut off the extra about 1 in (2.5 cm) below it. Do this before you install the zipper. If you’re working from a PDF pattern, check the notions list for the zipper length before you shop; the guide to printing PDF sewing patterns covers getting the pattern itself printed at the right size first.
Quick checklist
- Zipper longer than the opening, coils pressed flat on low heat
- Seam open, seam allowance marked, opening stabilized if needed
- Both sides sewn from the top down with the coil in the foot’s groove
- Cross seams marked on the tape and basted before sewing the second side
- Lower seam started 1/4 in (6 mm) above the zipper stitching, just outside it
- Zipper tail stitched to the seam allowances only
Frequently asked questions
- Can I sew an invisible zipper without an invisible zipper foot?
- Yes. A regular zipper foot works if you press the coils flat first and stitch slowly, keeping the needle right beside the coil. The stitching ends up a hair farther from the teeth, so a little of the zipper tape may show. An invisible zipper foot holds the coil open in a groove, which lets you sew closer and gives a cleaner result.
- What length invisible zipper should I buy?
- Buy a zipper longer than the opening, not the same length. The slider and the bottom stop need room below the end of the opening, and the last inch of coil is too close to the stop to sew neatly. Most guides suggest 1 to 3 in (2.5 to 7.5 cm) longer. Use the length your pattern lists, or shorten a longer one.
- Why is there a pucker or bubble at the bottom of my invisible zipper?
- The seam below the zipper usually starts too far from the zipper stitching, or it crosses over to the wrong side of it. Start the lower seam about 1/4 in (6 mm) above the end of the zipper stitching and slightly to its left, with the zipper tail pulled out of the way. A small gap is fine; an overlap creates a fold.
- Should I sew the seam before or after putting in an invisible zipper?
- After. An invisible zipper goes into an open seam: you stitch both sides of the zipper to the flat pieces first, then close the seam below it. If the seam is already sewn, unpick it as far as the zipper's bottom stitching point. Finishing the raw edges first, with a serger or zigzag, is easier while the pieces are still separate.