I remember my first attempt at an invisible zip: I didn’t know you needed a special foot, and as a result it turned out quite visible. If you’ve never sewn one either, I hope this tutorial will make your first try more successful! We’ll walk through the process step by step, and I’ve included a method to attach a lining as well. I’ll demonstrate it with the Amber Trousers, and we’ll follow those instructions. You can use it for any pattern that requires an invisible zip though. It is not a very complicated process but this tutorial is a bit long nonetheless, since I wanted to include a lot of photos for the visual learners. If you have any questions, leave a comment!
What You Need
- The Amber Trousers, made up until Step 6, or another pattern that asks for an invisible zip
- An invisible zip foot
- A normal zip foot
- A regular foot
- An invisible zip
- Washable glue stick (optional)
- Pen or pencil
As you can see I don’t have the ‘official’ Janome blind zip foot, but a generic one. I bought this after my first failed attempt and have used it since. It comes with three attachments (the blue part) so it fits every machine. It works the same as a metal one: the little knob at the front pushes the zip teeth away so the needle can stitch in the ditch right beside the teeth. If you don’t have an invisible zip foot, you can try it with a normal zip foot. It helps of you press the teeth open with your iron before you pin it in place so you can stitch close to the teeth.
The zipper you’re using should be longer than the actual length that the zip should open: it is not possible to sew all the way down to the end of the zipper because the pull will be in the way. The colour of the zip should not matter since it will be invisible, but I’ve found that it’s better to get a colour close to the fabric anyway, since it will probably still show a little bit at the places where it goes through a lot of layers, like the yoke seam. You can use nail polish to paint the zipper pull the right colour, preferably before you install the zip.
Step 1: Sew zip to front piece
If you’re using the Amber Trousers, by the time you come to the zip you’ve sewn the yokes to the pants and done a fitting session. The zip will be installed on the left side of the pants.
Lay the open side seam in front of you, right side facing up. Unzip de zipper and place it with the teeth down, the right side of the zipper on the left side of the side seam. The zipper stop at the top should be just under the yoke stitching line (at 5/8″ or 1,5 cm from the raw edge), the zipper placed so that the teeth are at the side seam stitching line. Pin it in place and mark the end of the stitching line as indicated on the pattern piece, just below the pockets.
If you want to be sure that it doesn’t move, you can glue it in place with a washable glue stick, or baste the zipper tape to the side seam first. Stitch the zipper in place with the invisible zip foot, from the top until the end mark. It’s OK if it’s a bit lower than the mark, as long as it ends at least 5/8″ (1,5 cm) below the double layers of the pocket.
If you’ve done it right, you’re not supposed to see the stitches when the zip is attached, only when you roll away the teeth. Close the zipper to see if it still runs smoothly. Make a mark (with a pin or pen) on the zipper tape at the yoke seam, so you can match it when pinning the other side of the zip.
Step 2: Sew zip to back piece
With the zip still closed, turn the pants inside out. Place the unstitched side on the back trouser piece, at the same position as the other zip half: zipper teeth down on the right side of the fabric. Pin in place. The glue is extra handy here to keep that mark exactly at the yoke seam. Check that the zip or trouser legs aren’t twisted.
Open up the zip so you can stitch it in place. Stitch from top to bottom so you have the least chance of that yoke seam mark shifting.
Close the zipper to see if it is actually invisible, if the yoke seams line up and if it runs smoothly. If you have a lot of zipper left over at the bottom, stitch back and forth over the teeth or sew it shut by hand just below the last stitches, so you can cut off the rest, about 1″ (2,5 cm) below the stitching.
Step 3: Close the seam
For my first couple of blind zips, I remember finding this the trickiest step in the whole process: to get a smooth transition from zip to seam. First, change to a normal zip foot. Pin the seams together below the zip end. Also pin the zipper tape and seam allowances together at the bottom of the zip, to keep it out of the way. This will help to keep the fabric on the underside smooth when you’re sewing.
Start sewing next to the backstitches of the zipper. Stitch as close to the zipper stitches as you can, which is about 1/8″ (2-3 mm). That’s OK, you don’t have to try to get closer. From this side it seems like it will look weird on the right side, but the zipper rolls in the fabric around the teeth a bit so it will take up that 1/8″ (2-3 mm) difference. Stitch on for 2″ (5 cm), down the side seam, backstitch. Check the seam on the right side to see if the transition is smooth.
Switch to a normal foot and continue the side seam to the hem. Press open, and also press the zipper on the right side of the fabric. Try the trousers on one more time for a last fit assessment. If you’re satisfied, take out the pocket basting stitches and finish the seam allowances. If you didn’t cut off your zip at the bottom, you can sew the two tails to the seam allowances to keep them in place. This might make the seam bulky in very lightweight fabrics, so just leave it when you’re working with a rayon or silk.
Step 4: Attach yoke facing
Next up is sewing the yoke facings. Start with sewing the yoke facings together at the right side seam. Press the seam open. Open up the zipper and lay the zipper tape open, the teeth towards the center front. Pin the yoke facing to the top of the yokes, right sides together. Stitch around the top of the yokes. Cut off the zipper tape right above the stitching.
Press the yoke facings away from the yokes and understitch the yoke facings to the seam allowance of the yokes. Fold the facing and seam allowance back over the yokes. You should be able to see both rows of stitching. Fold the raw edge of the yoke facing up so it falls just below the yoke seam underneath. Switch to a zipper foot and stitch the facing to the zipper tape, from top to bottom. Try to stitch close to the zipper teeth, about 1/8″ (3 mm). The beginning is kind of tricky since you’re sewing through many layers. Start a bit in from the top, backstitch to the top, then continue down.
Repeat for the other side. Snip off the corner and turn the yokes inside out. Push out the corners.
That’s it! An invisible zip with a neatly finished facing. We’ve used a yoke facing here, but the same goes for attaching a lining. Now you can move on to securing the rest of the yoke lining to the trousers. I hope this tutorial has made this step a bit less intimidating. If you have any questions, just leave a comment.