Sewing an Invisible (Concealed) Zipper into a Seam

Invisible zippers are sewn into a seam very closely to the zipper teeth, so that when the zipper is closed, it just looks like an ordinary seam – like no zipper is there at all! This can seem intimidating for beginner sewists, but invisible zippers have always been my favourite zip to install. This is because, unlike other zipper types, they require no topstitching after the zipper is sewn, which means they take fewer steps to insert into your seam. The key is getting the stitching very close to your zipper teeth to get that “invisible” effect. In this tutorial I’ll show you how to do that so you’ll have perfect invisible zips every time!

An invisible zipper can be installed into any seam where two fabric pieces are joining together. The Tulip Dress is a great candidate for an invisible zip! These closures are common on Centre Back (CB) seams, side seams, and even on detail seams (like adjustable slits in sleeve cuffs – check out Lisa Omori’s amazing Tulip Dress hack on her Instagram @gizagiza.gorogoro!). While these types of zippers will be perfectly suitable for day to day garments like pants, shirts, dresses, and light jackets, they are not sturdy enough for garments where the zipper joins many (or heavy) layers of fabric together. For example, in heavier garments like outerwear or layered garments like wedding gowns, an invisible zipper will not be able to hold the strain of all the supporting layers of fabric and can easily pop! But for normal daily garments, an invisible zipper is a great option for creating a sleek, almost seamless effect.

Invisible zippers can be identified by the smooth outer appearance (left side of image) – the teeth are only visible on the back (right side of image).

To install an invisible zipper, you’ll need;

• A pattern that requires a zipper closure
• An invisible zipper the appropriate length (as noted in your pattern)
• Thread that closely matches your fabric
• Fabric of your choice
• A zipper foot
• Optional: an invisible zipper foot*

*Many people love the invisible zipper foot, but I have always found that it does not sew close enough to the invisible zipper teeth, so I prefer not to use it. However, it does simplify the installation by unrolling the zipper for you, so if you prefer to use this specialized foot, I encourage you to do so! But if you don’t have one, you can still install a perfect invisible zipper with a regular zipper foot.

Depending on your sewing machine, your zipper feet may look different from the ones below. The notable differences between the two types of feet are: a regular zipper foot has a smooth surface underneath, with the needle position to the left or right of the foot. Many newer models will allow you to attach the foot to the left or right to make sewing easier. An invisible zipper foot has ridges on the underside to guide the stitching and unroll the invisible zipper teeth as you sew. It also often has a hole in the centre (rather than to one side) for the needle.

Once you’ve determined the sewing pattern to use, choose a zipper that matches or is slightly darker than your fabric. The zipper will fall into the seam and will be somewhat shadowed, so a slightly darker colour will help blend any visible portions of the zipper into that seam. Your thread should match your fabric. My thread is a different colour here so you can see what I’ve sewn more easily.

Start by pressing your fabric at the seam line. This crease will be your stitching line when you install the zipper. The sample in these images mimics the details of the Tulip Dress. The seam allowance at CB of the Tulip Dress is 1cm (3/8”).

The Tulip Dress has a waist seam. I’ve created my sample to have a horizontal seam to mimic this detail. It’s important to identify any horizontal seams joined by a zipper so you can align both sides of your garment to ensure a perfect match.

Unzip your zipper. With your fabric laid right-side-up, place your zipper along the edge so the teeth curl toward you. The zipper pull should be facing down, away from you. The top of the zipper should be aligned to the top of your garment in the amount of the recommended seam width. In the Tulip Dress, the neckline seam is 0.5cm (3/16”) so I have aligned the zipper stopper that distance from the edge of the fabric.

This step is useful for beginners but can be skipped once you’ve had some practice installing invisible zippers. In this step, you will stitch the zipper to the fabric to secure it in place to help with the next step. This is essentially staystitching the zipper – I recommend using a basting stitch length on your machine, and you can even remove the stitching once the zipper is installed. Using your regular zipper foot, sew along the middle of the zipper tape, approximately 0.5cm (1/4”) from the outer edge. You will not have to unroll your zipper to sew.

Once complete, you will have a seam along the middle of the length of your zipper tape. It’s OK if it is not completely straight – remember, you can remove these stitches once the zipper is fully installed.

Next, sew your zipper to your fabric, unrolling the zipper teeth to get your seam close as close as you can to the teeth. If you have an invisible zipper foot, now is the time to attach it to your machine. If you do not have an invisible zipper foot, you can follow the instructions and images below. Start at the top of your seam, aligning the needle close to the zipper teeth. A regular zipper foot’s edge will press against the teeth, unrolling them a little. An invisible zipper foot will straddle the zipper teeth, unrolling them for you as you sew.

TIP: Some folks like to use an iron to gently press on top of the zipper to help it unroll. If you are more comfortable doing this, feel free to do so! I don’t personally do this as I like to have as few steps as possible because I’m an impatient sewist 🙂 But I always encourage others to do whatever steps makes it easy for you.

Once you’ve sewn and backstitched the first few stitches, use your fingers to hold the zipper down on one side, and unroll the teeth on the other side, making them nice and flat as you sew. Keep your fingers close to the zipper foot to ensure the teeth are unrolled to get a good, close stitch. Sew along the zipper length to the zipper notch (if applicable), or as far as you can down the length of the zipper, backstitching at the end to secure the seam.

Zip the zipper closed and use a pin to mark where the waist seam is. Leave this pin in place to help you align the zipper on your other fabric piece.

Pin the zipper onto the other side of the fabric. Test that you’ve pinned it correctly – the zipper pull should be facing you, and the zipper tape should be twisting away from you, the left side mirroring the right side.

Repeat the steps above on the other side of the zipper tape. Sew as far as you can toward the end of the zipper, or to the zipper notch (if applicable).

Now that both sides of the zipper are attached, you may choose to remove the basting stitch to give your zipper a tidier look. This is optional. The next step is to finish sewing the lower seam of the garment, starting at the end of the zipper. First, look at where your seams end on each side of your zipper – they may not have been sewn precisely (as in my example), and that is OK. Identify the shortest seam (the one that ends the farthest from the bottom of the zipper tape). In the example below, the shortest seam is on the left side of the image.

Use a pin to mark the end point of the shortest seam.

You will begin sewing the seam closed starting just above that point. Use a regular zipper foot and position your needle as close as possible to the zipper seam that you previously sewed – approximately 0.25cm (1/8”). Be sure to backstitch at the start of your seam to secure the thread.

Sew down the rest of the seam, aligning the fabric along the creases you ironed earlier. The creases are meant to guide you, but do not worry if your alignment is a little bit off – you can re-press the seam to make it smooth after you’re done sewing. Gently hold the end of the zipper tape away from the needle as you sew, so it does not get caught in your seam.

When you are done, your seam will be approximately 0.25cm (1/8”) from the zipper seam. This small difference in seam position will be concealed once the seam is pressed.

Now that you’ve installed your zipper, you can install your facing. You may notice that your facing is approximately 0.5cm (3/16”) shorter than your garment piece (on the Tulip Dress, this is the neck facing, but this applies for pants and skirts as well). This is to compensate for the extra material provided by the zipper tape, as you’ll see in the next steps.

TIP: If you are serging or folding and stitching your lower facing edge, do so before doing the next steps.

To begin installing the facing, unzip the zipper and unfold the seam allowance so the zipper tape is visible. Align the facing to the garment at CB with right sides together.

Sew along CB at 0.5cm (3/16”), backstitching at both ends.

Next, you will attach the facing to the bodice, sewing along the neckline (or, if you’re applying your zipper to a skirt or pants, you’ll be sewing along the waistline). Fold the zipper toward the right side of the garment and pinch near the top to ensure your zipper tape is flat and that there is no excess fabric in your fold. You should be able to feel the zipper stop near the top of the tape – put a pin just above this stop to hold the fabric in place as you sew.

Be sure to sew above the zipper stop near the top of the tape, and within the recommended seam width. As a reminder, the seam width for the Tulip Dress neckline is 0.5cm (3/16”).

Trim the top of your zipper tape to remove bulk. Complete the process on the other side of the garment.

Fold your facing out, so that the right side is visible.

Edgestitch along the facing, approximately 0.25cm (1/8”) from the seam, being sure to press the seam allowance toward the facing (so your stitching catches the facing and the seam allowance). This will help ensure that your facing rests easily on the inside of your garment and does not pop out while you are wearing it. Begin your edgestitching approximately 4-5cm (1.5-2”) from the zipper.

Press your garment flat, and you are done! Happy sewing 🙂