I remember zippers being incredibly intimidating when I started sewing, but I promise they aren’t so bad especially with an invisible zipper foot. There are several steps to the process, but just take them one at a time and I think you’ll be pleasantly surprised.
1. Begin by drawing your seamline on the right side of your fabric. The Tap Shorts seam allowance in 5/8 inch or 1.5 cm so use a ruler to measure in this distance from the raw edge. You will want to mark the seamline on both the left front and left back. (Pattern Instructions Step 30)
2. A great feature of plastic invisible zippers is that they can easily be shortened. For this reason Grey’s Fabric only carries one size of invisible zip the longest, 22 inches, from which you can make any length of zipper you desire (well unless you need a zipper longer than 22 inches which is quite rare in my experience). Lay your invisible zipper along the seamline that we just marked with the top of the zipper tape even with the top of your waistband. Use tailor’s chalk or other fabric marking tool to transfer the zipper placement mark (the open circle on your pattern pieces) onto your zipper tape. (Pattern Instructions Step 30)
3. Measure 1 inch (2.5 cm) below your chalk mark and make a second mark on your zipper tape. Finally measure 3/4 inch (2 cm) below this second mark to make a third mark on your zipper tape. (Pattern Instructions Step 30)
4. Zig- zag stitch back and forth across your zipper and zipper teeth at the second mark. This will create a new zipper stop. Now just snip your zipper at the third mark (the farthest from the top of your zipper) and voila, custom length invisible zipper. (Pattern Instructions Step 30)
5. Set your iron to low (we don’t want to melt any plastic zipper teeth). Unzip your invisible zipper and you will notice that the zipper teeth roll towards the back of the zipper, this allows the zipper to be recessed in your seam when installed. However for now we need to unroll the zipper teeth so we can sew close to them. Use your iron to uncoil the zipper teeth from the wrong side of the zipper. (Pattern Instructions Step 31)
6. If you look closely you’ll notice two rows of stitching on the back of your zipper once the teeth are uncoiled. We’ll be sewing on top of or just next to this stitching. (Pattern Instructions Step 31)
7. Alright time to pull out that invisible zipper foot and put it on your machine. Pin your open invisible zipper face down (the zipper pull will be against your fabric, see bottom photo) to the front left leg (open front side seam) of your shorts. Use the seam line we marked in step 1 to place the zipper teeth 5/8 inch (1.5 cm) from the raw edge. The zipper teeth will be positioned towards the center of your shorts while the zipper tape will be towards the raw edge.
Position the left groove of your invisible zipper foot over the zipper teeth. Sew from upper edge of waistband to the zipper pull. (Pattern Instructions Step 32)
Now you have a row of stitching right up next to your zipper without catching any of the zipper teeth. Weee.
8. One of the trickiest things about invisible zips is not getting them twisted when you attach the second side of the zipper. Don’t worry I’ve taken a ton of photos! First close your zipper. (Pattern Instructions Step 32)
9. Now we are going to go back to working with right sides together for a moment. Right sides together bring back side seam to zipper. (Pattern Instructions Step 32)
10. The free zipper tape needs to be attached to the right side of fabric along your back side seam. Again the invisible zipper should be face down on the right side of your fabric. (Pattern Instructions Step 32)
11. Pin the top of your free zipper tape face down to the right side of fabric on your back waistband. The zipper teeth should be on top of the seam line we marked in step 1. (Pattern Instructions Step 32)
12. Unzip zipper.
13. Pin the rest of the zipper tape to the seam line on back (pattern piece 3). (Pattern Instructions Step 32)
14. When everything is pinned it should look a little something like this. (Pattern Instructions Step 32)
15. Place right groove of invisible zipper foot over zipper teeth. Sew from top of waistband until foot touches zipper pull. (Pattern Instructions Step 32)
16. Close zipper. Pin left front (pattern piece 1 & 2 or 8) to left back (pattern piece 3) along side seam below zipper. Change back to your regular presser foot and sew from bottom edge to as close to zipper bottom as possible. (Pattern Instructions Step 32)
17. You won’t quite be able to reach the zipper stitching. Stop before the fabric puckers or pulls. (Pattern Instructions Step 32)
I feel that in most cases you won’t even notice the short section that isn’t sewn to the zipper or into the side seam. Plus you have the end of the zipper tape behind this gap so you shouldn’t experience any peek-a-boo issues. However if you didn’t get as close as you wanted to the bottom of the zipper, you can just hand stitch the remaining bit. My opinion is that it is much better to stop sewing the side seam early so that you don’t stretch your fabric or create puckers and finish any gap with hand stitching.
And that’s it. You’ve sewn an invisible zipper. YAY!!!!!
I’m more than happy to answer questions so hit me up in the comments.