Posted On October 8, 2015
The invisible zipper is one of the most used fastening techniques. So I wanted to share the method we use to install an invisible zipper and to achieve a perfect finish. Sharing tips and techniques to solve problems along the way. Check out our corresponding YouTube Tutorial.
What is an invisible zipper?
Start by choosing an invisible zip – if you are unsure check what this looks like on the internet! Shops are notorious for selling the wrong thing if they don’t know what it is!
The teeth on the zip should not be visible from the front, the zipper pull will be small and the teeth will be visible from the back. There are different weights of invisible zippers. My only recommend would be to avoid the lightweight invisible zips if you are working with a garment that may take some strain or you are working with a heavy weight fabric.
Red Invisible Zipper – YKK
Brown Lightweight Invisible Zipper – Wholesale Brand
When can I use an invisible zipper?
An invisible zipper can be used in a variety of sewing projects, from dressmaking to home furnishing. On garments the invisible zipper can be used on tops, dresses, skirts and trousers. Generally it is used in the back or side seams of items to provide a flat finish with an invisible fastening. The only time an invisible zipper is not recommend is when you are working with a very thick fabric, or the garment will be under a lot of strain, such as a corset. Invisible zippers can break if put under a great amount of strain.
When looking at home furnishings the same rules apply, you can use an invisible zipper as a fastening on cushions, and they can even be applied to cushions with piping! However if the fabric is very thick the zip may struggle to fasten and unfasten easily.
What equipment do I need to sew an invisible zipper?
If you plan to sew a lot of invisible zippers purchase an invisible zipper foot. The invisible zipper foot will make the process of sewing an invisible zipper MUCH easier. However if you don’t have an invisible zipper to hand it is still possible to sew an invisible zip using a standard sewing machine foot (it just take a bit more practise)!
You will also need a standard zipper foot (these come with most sewing machines), a ruler, some scissors and a removable marker of some description.
We will be sewing using a different colour fabric, zip and thread for illustration. However you will aim to choose the zip and thread that blends in best with your fabric.
You MUST sew an invisible zipper into a seam, before sewing up the seam of the garment.
The invisible zipper must be sewn into position before the garment is sewn either at the bottom of the seam, or on either side of the zipper (bottom and top) if you are working with a zip in a cushion cover or side seam. I would recommend putting the zip into the garment as soon as possible during construction. It is easier to work with when your fabric is flat and before you have joined lots of garment seams together.
The red zip on the left of this image is a YKK Invisible Zipper, the brown zip on the right is a un-branded cheaper invisible zipper, purchased from a wholesale supplier. Here you can see the difference in the zipper tape, the red zip has a thicker zipper tape than the brown zip. As I mentioned previously if you are using an invisible zipper on a thick fabric or a garment that may take some strain I would recommend using the YKK Invisible Zipper (red zip) with the thicker zipper tape.
Take your fabric that you are working with, and the seam where you plan to add your invisible zipper.
You will need to start by drawing your seam allowance (standard seam allowance is 5/8″ (1.5cm)) onto the RIGHT side of the fabric. Drawn down the full length of the seam (where the zipper will be introduced) using a removable marker such as chalk.
If you are working with a garment, generally a facing or waistband will be placed at the top of the zip. Therefore you will need to measure down from the top edge of the fabric 3/4″ (2cm). This will create a neat finish at the top of the zip when you introduce the waistband or facing. If you will be sewing across the top of the zip using a seam allowance of 5/8″ (1.5cm) to attach the waistband or facing, mark 3/4″ (2cm) below the top edge of the fabric. This will provide you with a small amount of extra room, which will stop you from sewing over the top of the zip (getting the zip caught in this seam creates a bulky seam, and the zip will never do up to the top) plus it provides a professional finish.
You do NOT need to mark the ending point of the zip if you have purchased the correct size zip for your project / pattern.
What if you don’t have the right size zip?
If you don’t have the right size invisible zipper you are welcome to use a longer zipper and cut the zip down to side after sewing. You do NOT cut the zip down first as you would a standard zip.
Simply mark on the fabric where you would like the zip to stop with a horizontal marking.
I plan to sew the seam closed at the top and bottom of the zip?
If you are planning on making a cushion cover, or positioning the zip into the side seam of a garment (top or dress), you will most likely need to sew the seam above and below the zip.
In this instance you will need to mark a horizontal line across the top (where you want the zip to start), and the bottom (where you want the zip to end).
If you don’t have an invisible zipper foot you will need to iron the teeth of the zipper away from the tape. This will allow you to sew in the groove, as close to the teeth as possible. If you do not iron the zip you will fit it very difficult to sew close enough to the teeth to create an invisible finish.
You do NOT need to complete this step if you have an invisible zipper foot, as the foot will pull the teeth away from the zipper, allowing you to stitch in the perfect position.
Iron the teeth away from the zipper tape using heat and steam. Don’t hold the iron onto the zip for too long, you don’t want the teeth to melt!
Position the zipper onto the fabric, to position the zipper correctly into the fabric you will need to place the RIGHT side of the zip onto the RIGHT side of the fabric. With the teeth of the zip facing AWAY from the seam allowance (edge of the fabric).
To achieve this either unfasten the zipper and open both sides outwards, like opening a book! Alternatively some people prefer to fold the fabric onto a closed zip, to achieve the finished look. Hold the fabric onto the zip, as you unfasten the zip – this will confirm that you are attaching them in the correct manner.
Position the teeth of the zip onto the drawn line, and position the clear zip stopper at the top of the zip on the horizontal starting line you drew previously (top edge of the fabric).
Pin the zip in position with the point of the pins facing the top of the zip, this will make the pins easier to remove when sewing. I personally don’t tend to baste the first side of the zip, however you are welcome to baste, tack the zip onto the fabric should you prefer this method.
You may find it easier to baste or tack your zip onto your fabric if you do not have an invisible zipper foot.
At the sewing machine change the standard foot to the invisible zipper foot. If you don’t have an invisible zipper foot I would recommend using a standard zipper foot.
If you are working with an invisible zipper foot take the top thread through the hole in the foot so that both threads are out of the way (underneath the foot). To do this, wheel the hand wheel on the side of the machine one full rotation (for the needle to drop down and back up). This should then allow you to collect the top thread from underneath the foot using a pin.
When working with an invisible zipper foot the only thing you need to worry about is getting the zipper teeth into the correct groove. The invisible zipper foot as two grooves, when sewing any invisible zipper you will always use BOTH grooves (one for either side of the zip). You must always sew the invisible zip from the TOP down.
For the first side we will be using the LEFT groove on the foot, because we want the needle on the sewing machine to sew to the RIGHT of the zipper teeth (as close to them as possible).
It can be difficult to get the teeth into the groove to start, especially because you will be starting at the top of the zipper tape where there are no teeth. Get your eyes level with the bottom of the foot and check that it is in position, you may need to pull the teeth open slightly with your fingers when sewing.
Start sewing at the top of the zip and back stitch to secure the stitching. As you move along the zip to the start of the teeth check that the zipper foot is still in the correct position.
Sew along the zip, gently pull the teeth open with your fingers. Stop when the foot touches the zipper pull at the end of the zip (you will not be able to sew any further than this). Back stitch.
How to sew an invisible zip with a standard zipper foot.
To sew the invisible zipper onto the fabric with a standard zipper foot you may need to move the needle on your sewing machine in line with the edge of the zipper foot, this will allow you run the edge of the zipper foot against the teeth, sewing as close to the teeth of the zip as possible, but NOT on them. On my sewing machine the needle will only move to the far left (in line with the standard zipper foot), you sewing machine may be different.
Having pressed the teeth of the zipper away from the zipper tape there should be a very slight line visible on the zipper tape, very close to the zipper teeth. This is a good starting point – try and follow this line for ease. You might find it easier to baste or tack your invisible zipper onto your fabric if you are working with a standard zipper foot.
Before moving onto the second side of the zip check that the zip will fasten. If it doesn’t you may need to unpick the stitching and start again.
Have I gone wrong sewing an invisible zipper?
There are two things that can happen. You can sew too far away from the zip, this will make the zip look visible in the product. This is easy to do if you aren’t working with an invisible zipper foot and the simple solution is to sew along the zip again, closer to the teeth. Ideally you want to sew directly next to the teeth of the zip (not on them), there is a slight line on the zipper tape close to the zipper teeth – this is the perfect position for sewing. You do NOT need to unpick the sewing in this instance as your first line of stitching will be invisible when finished.
The other problem can be that you have sew too close to the zipper teeth, sewing over the teeth slightly will mean that you cannot fasten the zipper. In this instance you will need to unpick the previous stitching and try again. This is why we check that the zip will do up after sewing before moving onto the second side.
On the second side of the zip, you will again open the zip like a book and position the RIGHT side of the zip, onto the RIGHT side of the fabric, zipper teeth facing into the product. Check that your garment or product is sitting flat and that you haven’t twisted any of the pieces (you must check this if you have already sewn most of the garment together, it is very easier to sew the zip into a twisted garment!)
Start by pinning the zip with the teeth sitting on the drawn line. The stopper at the top of the zip MUST sit on the drawn line at the top of the fabric. Compare BOTH sides of the zip together, to check that the start of the zip will be in the same place. This is very important because if the start of the zip is the same on both sides, the rest of the zip should be the same as you will always sew an invisible zipper from the TOP down.
Lay the two pieces of fabric next to each other, line up the top edge of the fabric and check the top edge of the zip and the zip stopper are in the exact same place. Pin in position.
As you get to the bottom of the zip you will need to position the other side of the fabric and sewn zip out of the way. To allow you to pin to the bottom of the zip.
CHECK – if you are working with a garment check that you haven’t twisted the garment during this stage. You want everything to sit straight; which is why it is easier to sew the zip into the garment before joining the other pieces together.
If you are working with a patterned fabric or a garment that has seams that need to match along the zip I would recommend basting or tacking the second side of the zip in place. Start by positioning the pins away from the teeth, this should allow you to fasten the zip as an initial check. Check that the required areas match up and then baste or tack the zip onto the fabric. Before sewing check that when fastened all of the pattern and seams match along the length of the zip.
At the sewing machine complete the same on the other side. Position the teeth of the zip in the RIGHT groove and sew to the LEFT of the teeth.
Once you have sewn the other side of the zip, fasten the zip to check that everything is ok.
You may find that the zip can look twisted. If however during pinning the second part of the zip you kept everything flat and NOT twisted you should just find that you need to flip the material around to free up the zip. Check out our corresponding video to see this in action – Link!
Now it is time to sew up the seam below the zip. In some cases you may be sewing the top of the zip closed too; such as a cushion cover, dress or top with an invisible zip in the side seam.
Lay the fabric RIGHT sides facing each other. You will need to sew up the bottom seam of the garment and past the stitching completed for the zip by about 3/8″ (1cm). This can be completed in one full stitching line from the bottom of the garment up to the zip, sewing as close to the zip stitching as possible (1/8″ (3mm) away). You will need to sew this with a standard zipper foot so that you can sew close to the stitching line of the zip.
Sewing the whole of the seam with the standard zipper foot can be difficult to complete and most of my customers prefer to sew the process in two steps. Starting by sewing the area at the bottom of the zip and then finishing the rest of the seam.
It can be helpful to mark the stitching line on to the fabric with chalk or a removable pen.
On the sewing machine that I am working on, the needle can only move to the far left. Therefore I have set up the needle to be on the far left (in line with the zipper foot), this will allow me to sew as close to the zipper stitching line as possible. However it does mean that the fabric has to go through the sewing machine (on the RIGHT), with the fabric inside the nook of the machine (opposite to normal).
Start sewing about 5/8″ (1.5cm) from the bottom of the zip. Hold the zip and seam allowances of the fabric out of the way, sew up along the drawn line as close to the zip as possible, sewing about 1/8″ (3mm) away from the zip stitching and 3/8″ (1cm) past the bottom of the zip. Back stitch to secure the stitching.
Once you have sewn the area around the zip closed, sew up the bottom of the seam using the required seam allowance. Back stitch at the start and end of sewing to secure the stitch.
You can sew this with the normal foot for ease, and with the fabric on the left of the machine! Remember to position your needle back to the centre so that your seam allowance guides are correct! You will sew this with your standard seam allowance of 5/8″ (1.5cm), or whatever your pattern dictates.
Complete as above for the top of the zip if required, this is common when the zip is used in a side seam of a dress or top and a cushion cover. You will need to open the zip to be able to sew past the start of the stitching at the top of the zip. Open the zip and pin the edges of the zip together to hold it closed whilst you sew as close to the stitching as possible and 3/8″ (1cm) past the start of the zip.
Press the bottom of the seam open. I personally don’t tend to press the zip, it can cause indentations in the fabric.
To finish the zip I would recommend attaching the bottom of the zipper tape onto the seam allowances. This will stop the zip from moving and poking out at the bottom (very useful if you are working with an unlined garment).
Position the zipper tape onto the seam allowance, and sew through ONLY the seam allowance. Stitch forwards and backwards a couple of times to create a bar tack.
Complete on both sides as below.
Congratulations you have sewn an invisible zipper, hopefully you are happy with your perfectly finished zip and feel able to sew invisible zips in future projects. Why not share your makes with us on Facebook, Twitter, Instagram!