Invisible zippers are indispensable to fashion sewing. It is the choice form of fastening for most dresses, skirts, formal gowns, trousers, and other lightweight garments. Mastering invisible zippers is an important skill you can’t do without.
Ideally, an invisible zip is attached before completing the garment seams. The photos below show the procedure step-by-step.
The zip as seen on the wrong side
The zip (un)seen on the right side.
Now, you have a neat-looking invisible zip with side seams closed.
On the top edge, mark the point where the zipper stitch starts and stitch from the top edge to that point.
Now, we will close the seams on top and at the bottom of the zipper (this is the side seam of the garment). Bring the two fabrics to one side, right sides together. Mark the point where the zipper stitch ends. Stitch down from that mark all the way down to the hem of the dress.
Done correctly, the zipper should be invisible when fully closed.
Repeat the steps on the other side. You can either stitch from the bottom up or from the top down. Don’t forget to adjust the zipper foot accordingly.
A close up of the finished side.
Using the zipper foot, stitch the zipper starting at the top edge. Get as close to the teeth as the foot would allow you. Stop stitching an inch before you reach the bottom end of the zipper.
This is how it should look like at the bottom
Open up the zipper and position the top end an inch from the top edge. Pin one side to the edge of the fabric beside it. Twist the zipper so that the teeth faces away from the edge.
Align the two fabrics you want to join side by side, right sides up. Lay the zipper between the fabrics, right side also up