Zip-A-Dee-Ay! Please meet one of our favorite zipper friends: the invisible zipper. Remember, this zipper is shy, and likes to stay hidden in the seam line of your projects. In fact, with the exception of its slender zipper pull, you’d never know it was there. It likes it that way… and you will too! In the Realm of all Zippers (a land just north by northwest of Oz), the invisible or concealed zipper is actually the easiest to install.
Like its conventional counterpart, the invisible zipper is available in a wide range of colors and lengths, and comes in both standard and separating versions. Lengths average from 7″ to 22″. There are much longer lengths available, but in limited colors, usually just black and white. White is often used in bridal projects. The separating invisible zippers are a common choice in other special occasion gowns, and also a favorite for long, styled sweaters.
On an invisible zipper, the teeth have a coil structure, usually made of a flexible nylon. The teeth are attached on the reverse side of the zipper tape, so when the zipper is closed, the zipper sits underneath the seam and the tape, making it invisible. The tape itself is usually made of polyester.
In addition, the pull on an invisible zipper is a thin teardrop style, which is much different than the chunky pulls on regular zippers. This shape is designed to blend into the seam.
Invisible zippers are used whenever you do not want the zipper to be seen and/or to become a part of the overall design of a sewn project. They are normally centered within a seam. You wouldn’t use one in a fly front for a pair of jeans, but probably would choose them for zippers in the side or back seams of garments, special occasion wear, costumes, etc. We like them in home décor projects as well, such as along the edge of a decorator pillow or pillow sham.
The invisible zipper is installed in a different manner and with a very specific foot. Ready to give it a try?
Tools you’ll need
- Concealed zipper foot: This is a must have! You have to sew very, very close to the zipper coil, which requires a special foot. A concealed zipper foot has two grooves, one for the left side of the zipper and one for the right, allowing you to sew super close. When completed, the zipper closes at the seam line, and disappears.
- Standard Zipper foot: (Above right) Once you’ve sewn the zipper in place, you’ll need to use your standard zipper foot (the one that came with your machine in the standard set of accessories) to sew from the bottom of the zipper along the remainder of the seam. It’s a tight squeeze at the bottom of the invisible zipper, which you’ll see in the steps below, so you still need a special foot to sew in this area.
- Adjustable zipper foot: (Above left) This is an optional foot for most sewing machine models. It also allows you to sew very close to the zipper teeth. You can use this foot for installation and along the bottom of the zipper for the remainder of the seam.
- Seam gauge: An invisible zipper has to be exact parallel when you close it, which means your seam allowance must be maintained all along and beyond the end of the zipper. Using a seam gauge helps you determine exact positioning.
- Iron and ironing board: Although these should be an essential part of your sewing space, like sewing machine needles, and thread; we want to make sure you have them at the ready for this particular tutorial… you’ll see why later!
- Straight pins
- Interfacing – It’s often a good idea to have added support on the wrong side of the fabric where you’ll be installing the zipper.
- Fabric marking pen or pencil
Steps to install an invisible zipper
Fabric and zipper preparation
- As we mentioned above, adding a little support behind the zipper is often recommended. This is done with a layer of interfacing on the wrong side of the fabric. A narrow strip equal to your seam allowance will do the trick. You can use either fusible or sew-in interfacing, but it should be compatible with the type of fabric you’ve selected.
- Before beginning the installation process, consider finishing the raw edges of your fabric. A finished edge makes it less likely those little stray fabric threads will get caught in the zipper once it’s in place. For our example, we chose to use an overlock stitch on a serger. You can do the same, or use an similar overedge stitch on your sewing machine, such as a zig zag.
- Iron the invisible zipper along each side to uncurl the teeth. By doing this, you will be able to sew accurately along the edge of the coil. If you don’t do this, your invisible zipper might not be so invisible after it’s sewn in place. Be sure to use the synthetic setting on your iron, otherwise you could melt the nylon teeth.
Positioning and securing in place
- This is another key step! You have to be accurate with the zipper placement. First, if at all possible, do not sew any portion of the seam prior to installing an invisible zipper. This zipper is best installed with the two sides of the seam loose from each other. Place the two interfaced/finished fabric pieces right side up on your work surface.
- A zipper has a right and wrong side, just like fabric. An invisible zipper must be placed right sides together with your fabric, working with one side of the zipper, then the other. Repeat after me: “Right Sides Together!”
- The zipper coil has to line up with the seam allowance. For this, use a seam gauge for positioning. From the coil to the edge of your fabric should equal your seam allowance. In our example, our seam allowance is ½ “.
- If it helps you to be extra precise, you can draw in your seam line with a fabric marking pen or pencil so you know exactly where to place the zipper coil.
- If you’re using the center installation method, you will place the top of the zipper in from the raw edge ½” to ⅝” – the width of your seam allowance. If you’re following the inserted installation method, then you will center your zipper equally from either raw edge, such as along the edge of a pillow. If you’re following a pattern, it will tell you exactly where to place the zipper. Check out the Regular Zipper Installation tutorial for more details about the installation types.
- Pin one side in place.
NOTE: Some people prefer to sew the pinned side now, then pin and sew the opposite side. Perhaps this is how you learned. However, we prefer to pin both sides, then sew both sides, so this is how our tutorial is designed.
- Pin the other side in place.
- We believe this is probably the most confusing part about invisible zippers. If you step back, you can see when we place the zipper tape right sides together with the fabric, the zipper will seem like it’s twisted, but it’s not! Once it’s zipped closed, the fabric seam allowance will turn to the wrong side with the zipper. This is one of those sewing-mind-bender situations. You just gotta roll with us and trust us it will all work out in the end.
- If you’ve already reviewed our tutorial on basic zippers, you know what we’re going to discuss here. Yet another key step to success is using a proven method to secure the zipper in place prior to sewing. You can use a few different methods, hand-basting with needle and thread, machine basting, or by placing sewing tape across the zipper. Of course, you can also use straight pins to hold the zipper in place, but some people feel these become too cumbersome and actually prohibit you from keeping the zipper aligned properly when under the foot of the sewing machine.
- Especially when you’re new, the best method is to hand baste your zipper in place. It allows the most control over positioning as well as an easier way to test the zipper before final sewing.
- Sometimes you will want to maintain a motif in your fabric across the seam, or line up seams across from each other, such as at the waistline on a dress. This is the time to check and make sure your patterns are lining up.
Sewing the zipper
- Now that the zipper is in being held in the exact position you want, you’re ready for sewing.
- Attach a Concealed Zipper foot to your machine.
- Select a straight stitch, and adjust the length slightly. You want to account for the thickness of the zipper tape, fabric and interfacing. We set our length at 2.5 mm.
NOTE: Also remember to use the appropriate needle type and size as well as the appropriate thread for your selected fabric.
- Contrary to basic zippers, you sew invisible zippers from the top down on both sides.
- You can start on whichever side of the zipper is most comfortable for you. We are working on the right side first.
- Insert the top of the zipper into the appropriate groove on the Concealed Zipper foot. If you look closely, you can see this step is where pressing the zipper pays off. The zipper lays nice and flat. Also, the metal toe on the front of the Concealed Zipper foot pushes the coils to the side so the needle can sew exactly where it needs to for a perfect invisible zipper seam.
- Begin sewing, take a backstitch or two, then continue as far down as you can go until you reach the zipper pull. Backstitch again at the bottom. Be sure to sew slowly, it helps with accuracy and prevents puckering.
- Repeat on the other side from the top to the zipper pull.
- Slide the zipper pull up to close the zipper, and admire your work so far.
- Press along the zipper on the outside.
NOTE: Make sure your iron is on the appropriate setting for your fabric type. You can also remove any thread basting at this time.
- Wait! You’re not quite finished. You have to sew the remainder of the seam below the zipper so there isn’t a gap between the zipper and the seam.
- Remove the concealed zipper foot, and attach a standard Zipper foot or Adjustable Zipper foot. We used a standard Zipper foot. If appropriate for your fabric, shorten the stitch length. Close the zipper.
NOTE: Depending on the foot you use, you will be able to begin stitching right where you ended, or you might have a tiny gap between stitching lines. Either is acceptable.
- This step can seem a little difficult. The bulk of the zipper is right where you need to begin sewing. You have to hold the seam (that has the invisible zipper sewn in) off to the side a bit in order to expose where the stitching ended. Remember, your zipper is closed and the right sides of your fabric pieces are together… just as they would be to sew a regular seam.
NOTE: If your standard Zipper foot is preventing you from getting close enough to the previous stitching, (depending on your particular sewing machine features) you can adjust the width of the straight stitch, which will move the needle over.
- Lower the needle where you want to start the stitching. This is usually a few stitches above where you ended the previous stitching.
- Begin to sew, stop, backstitch, then continue to sew the seam. Sew past the remainder of the zipper and along the seam line as far as you need to go.
- Now, you’re done! And, the shy invisible zipper is now your friend.
Hints & Tips
- Instead of the recommended methods for securing the zipper in place we mentioned above, some prefer to use a fusible product, such as Stitch Witchery or similar to hold the zipper in place.
- Depending on the brand and the actual size of the coil, some invisible zippers glide more smoothly through a concealed zipper foot than others. If you find yourself using an invisible zipper with larger teeth, you can use your regular zipper foot. Depending on your make and model of sewing machine, you may be able to adjust the width of your straight stitch, which means you can move the needle left or right. This will help you get as close as possible to the teeth with a regular zipper foot. But… a word of caution, take it super slow so you don’t come down on those teeth with the needle and break the zipper as well as potentially damage your machine.
- Use a fabric marking pen or pencil to mark where the seams need to line up along the zipper, such as between the bodice and skirt of a dress. This helps you with positioning.
- For an added finished look, you can sew another line of stitching along the edge of the zipper tape and seam allowance edge to secure the zipper in place.
- Take a look at our tutorial on installing regular zippers for other general zipper Hints & Tips that also apply to invisible zippers.
Sample Creation and Instructional Outline: Jodi Kelly