This is a case where there is a seam in the middle of the back pattern. This zipper insertion is very easy so it is regularly used for center back or center front opening. This is not used for side openings.
Important : When you cut the pieces for the dress with a center seam, to add a zipper, you have to add atleast 1 inch as seam allowance to each edge.
How to sew a zipper if the dress has a centered seam
Step 1. First you have to Stitch them together with the 1 inch seam allowance; Where the zipper opening is marked should be sewn with a long basting stitch on the sewing machine. The rest you make a regular plain seam with a straight stitch.
Step 2. Finish the edges of the centre seam with a serger or zig zag stitch. Press the seam open.
Step 3. Line the zipper face down on the seam line. The zipper teeth will be in line with the center of the seam.
Pin the zipper in place. Place a pin just under where you want the zipper to end.
Step 4. We will be sewing from the bottom. First we have to sew the bottom of the zipper. Turn the
fabric so that right side is facing you.
Run a few stitches parallel to the pin you have placed on the mark for bottom of the zipper. Back stitch here if you want to.
Pivot and stitch along the zipper teeth.
Do the same thing for the other side as well. You will have to change the zipper foot side if you are sewing from the bottom in the other side.
Step 5. Unpick the basting stitch from the front, very carefully. Your centered zipper is ready. Now you can go ahead and finish the neck facing.
How to sew the zipper if the dress does not have a center seam ?
Step 1. Mark the center back of the back pattern, by folding it aligning the sides. Mark the length of zipper opening in the centre fold line.
Step 2. Cut another piece of cloth for the facing with length = length +2 inch & width = 3 inch
Step 3. Mark the zipper opening in the middle of facing piece in a straight line from top to the mark for zipper opening. Finish the edges of the facing cloth.
Step 4. Pin the facing piece to the bodice piece, center line matching, right sides together.
Step 5. Stitch around the center line with a 1/4 inch seam allowance, coming to a point at the bottom. The bottom should be stitched one or two stitch horizontally as shown in the diagram.
Step 6. Cut through the center line. Make small snips in the seam allowance and near the point at the bottom make diagonal snips (thread snips is your friend here). This will make the turnings smooth.
Turn to the other side. Press in place
Step 7. Behind one edge, Keep the zipper open, right side facing you; stitch close to the edge. Use the zipper foot to stitch close to the edge.
Step 8. Like the lapped zipper, on the other side, keep the open zipper a little to the inside. Stitch parallel to the seam. Make a horizontal stitch at the bottom of the zip.
Sewing zipper to a side opening of a dress
This is a great zipper application for the side openings in dresses. It conceals the zipper opening nicely.In case it is a side opening, hand stitch the zipper top closed for the time being (i.e. the top 1 inch of a zip)
Step1. Sew a plain seam for the center seam leaving the zipper opening. Now baste the zipper opening by hand stitching or machine with long basting stitches.
Step 2. Press the seam open.
Step 3. Keep the bodice wrong side up. Place it so that one seam allowance of the central seam is on one side and the rest of the garment on the other side.
Step 4. Open the zip. Now keep the zip on the central seam, wrong side up, aligning the zipper teeth directly on top of the seam. Pin in place. Baste stitch along the seam allowance, where you have pinned.
Step 5. Flip the fabric so that the zipper front is facing you to one side of the cloth. Now there is a fold near the zipper teeth. Stitch along the edge of this fold.
Step 6. Close the zipper. Now turn to the front of the fabric and sew some 1/4 inch from the center seam catching the zipper seam allowance also. Make a horizontal stitch at the bottom.
Stitch up the side of the placket through three thicknesses — the zipper allowance, the seam allowance, and the garment. You can sew this from the wrong side of the garment too.
Remove the machine-basting.
Step 7. Unpick the stitches on the seam carefully now. Your zipper side opening is ready.
