Option 1: Sarah’s Method for Inserting an Invisible Zipper
- Put your invisible zipper foot on the machine.
- For a clean invisible zipper application that lets the zipper come to the very top of the garment, work with an invisible zipper that is at least 3” longer than the desired zipper opening. With the zipper unzipped, place the bottom of the zipper so that the zipper opening is approximately 1/2” below the intended pants opening.
- Apply the zipper to the pant right back. Pin or thread baste the zipper in place, laying the right side of the zipper to the right side of the garment and positioning the zipper tape so you will get a 5/8” seam allowance. Uncurl the zipper teeth near the waist with your fingers, and place the foot so the zipper coil sits inside the proper portion of the zipper foot. Machine stitch it in place, stitching from the waist down and back stitching at the bottom.
- Close the zipper and make a very small clip in the zipper tape for the left back, making the clip level with the top of the right back pant. Unzip the zipper a few inches and pin just the top of the zipper for the left back in place, aligning the clip on the zipper tape with the top of the left pant back. Close the zipper and check that the top edges of the pants are even. Adjust the zipper position if necessary.
- Unzip the zipper and pin or thread baste the zipper in place for the left back. Machine stitch the left pant zipper as you did for the right back.
- Close the zipper and check that the stitching is close enough to the zipper teeth. You should not see much, if any, of the zipper tape when the zipper is closed. When working with piled fabrics such as corduroy, your stitching will need to be about 1/16” to 1/8” away from the zipper coil. Stitch again with the stitching closer to the zipper teeth if necessary.
- There will be a small portion of the crotch seam that is not stitched just below the end of the stitches that secure the zipper. Change the machine foot to a regular zipper foot; you may need to adjust the needle position slightly to finish the following steps. Place the point of a pin into the work where the stitches applying the zipper ended. Make sure the pin is at the end of the stitching line on both the right and left pant back. Now, pull the loose end of the zipper tape slightly away from the work and bring the pin up through the seam allowances of the crotch seam, slightly angling the pin away from the base of the zipper.
- Stitch along the seam line of the unstitched portion of the crotch curve, stitching on top of the previous stitches for about 1”, ending one or two stitches away from the pin at the base of the invisible zipper and leaving long thread tails. Remove the work from the machine and check that the stitching is on the seam line and near where the pin first entered the work on the portion of the garment that was against the throat plate of the machine. Remove the stitches and re-stitch if necessary.
- Thread one of the thread tails onto a hand needle and make the final stitch or two by hand, ending with both thread tails on the same side of the work. Tie a double square knot (tie one square knot, then a second square knot) and clip the thread about 1/2” from the knot.
- To secure the loose end of the zipper tape at the base of the zipper, stitch the edge of the zipper tape to just the seam allowance of the crotch curve, on both the right pant leg and left pant leg.
- Close the zipper and press lightly. To ensure that the fabric completely covers the zipper teeth where the waist seam intersects the zipper, open the zipper and, working with the right side of the garment against the ironing surface, slightly roll the garment fabric out about 1/16” to 1/8” so that you can see the folded edge of the fabric behind the zipper coil.
Option 2: Rae’s Method for Inserting a Lap Application Zipper
- Put your standard zipper foot on the machine.
- With the right side of the pant back facing you, fold under the right seam allowance of the zipper opening and press. Lay the zipper under the right side of the opening, placing the folded edge of the pants up against the right side of the zipper teeth. Pin the fabric to the zipper tape. Baste if desired, then stitch very close to the zipper teeth along the fabric edge.
- Fold the left side of the opening under 5/8” and press. Lap this folded edge over the closed zipper so that it just covers the stitching on the right side of the application. Pin the zipper tape to the left back approximately 1/2” inside of the folded edge. Baste the zipper tape in place, going through the pants fabric and the seam allowance.
- Unzip the zipper to make sure you have not caught the teeth in the stitching. Once satisfied with the placement, machine stitch the left side of the zipper in place. Stitch from the waist down the left side, and then pivot the work and stitch across the bottom of the zipper, back stitching at the seam line.
- Test the zipper once more to make sure it works properly.
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