I was working on my bias shirt today, installing the zipper in the back. It’s a centered application, which I actually like, but it can have disastrous results if not done properly. So I thought, “Hmmm, maybe there’s a tutorial here that might help some folks. So here you go. This way works for me; hopefully it can help you too.
Step 2 – Hand Baste the Zipper Into Place
This is probably the most critical part of the whole operation. In most commercial patterns, the instructions tell you to machine baste the zipper in place, then sew in place. The problem is that with most fabrics, machine basting will cause slippage, and then when you sew the zipper, you will get bubbles and puckers, the hallmarks of “Happy Hands at Home” syndrome.
Notice something in the picture. The zipper teeth are set very slightly back from the basted seam, probably a scant 1/16th of an inch. This will keep you from getting “zipper gaposis”.
Next, close the zipper and baste the other side. Here again, you will want to pull the zipper toward the raw edge of the seam as you baste so that, when opened, the teeth are ever so slightly offset from the folded over seam allowance to keep the gaposis at bay.
There is only one tricky part to this operation. To keep from getting a stitch “bubble” around the zipper pull, open the zipper before starting sewing. Once you get about half way down the zipper, drop the needle into the fabric, lift the presser foot, and carefully close the zipper (you’ll be working from the underside of the fabric). Once the zipper is closed, lower the presser foot and continue sewing. Pivot at the bottom of the zipper, and sew to, but not all the way across, the zipper, avoiding the metal zipper stop.
Repeat this step on the other side. Here’s the other important part: To avoid needless bubbles and distortion, start at the same place, but on the other side of the zipper, so you sew both sides in the same direction.