How to Trim Fabric in Sewing a Zipper

The first step in installing a zipper is to prepare the fabric. For most garments and bags, you’ll sew the area below the zipper together as usual, then baste the zipper opening closed. This will give the fabric clean, crisp edges when you install the zipper. Trimming the fabric free of any loose threads or raveling edges can also help make the zipper installation go smoothly, since stringy fabric edges can catch in the zipper teeth and prevent it from opening and closing properly. You may also need to trim the upper edges of the fabric when shortening the top of a zipper, or troubleshooting a zipper that’s not long enough. Read on to learn more about how to trim fabric in sewing a zipper.

Difficulty: Easy

Instructions

Things You'll Need:

• Scissors
• Fabric
• Thread
• Straight pins
• Sewing machine
• Iron

How to Prepare Fabric for a Zipper

1. Sew the fabric together following the pattern directions. Sew any seams near the zipper opening using a normal stitch length.

2. Trim the edges of the fabric opening so that they’re straight and even.

3. Clip any loose threads or raveling edges of the fabric so they won’t get caught in the zipper.

4. Place the two sides of the fabric right sides together and line up the edges of the opening.

5. Pin the edges of the opening together.

6. Set the stitch length on the sewing machine to the longest length.

7. Baste the edges of the fabric together using 5/8 inch seam allowance.

8. Press the seam allowances open.

9. Trim any loose threads or raveling edges on the seam allowance. Now the fabric is ready to have a zipper sewn to it.

How to Trim Fabric When Shortening a Zipper

10. After sewing the zipper to the garment or bag, open the zipper by pulling the zipper tab down a few inches below the top of the fabric.

11. Put a pin in the zipper about 1/4 inch below the top edge of the fabric.

12. Just below the pin, stitch back and forth a few times across one side of the zipper teeth, zipper tape and seam allowance. Do not stitch through to the outside of the fabric.

13. Repeat Step 3 for the other side of the zipper.

14. Cut off the top of the zipper just above the stitching.

15. Trim the top edge of the fabric if needed so that it’s no more than 1/4 inch above the top of the zipper.

16. Finish the top edge of the fabric by adding a facing, collar, waistband or hem.

Tips & Warnings

• If the zipper isn’t quite long enough to reach all the way to the top of the fabric, you can trim the fabric slightly so that it’s no more than 1/4 inch above the top of the zipper pull. If the zipper is much too short, you may need to replace it with a longer zipper, or add a hook and eye above the zipper.
• Use caution when working with sewing machines, scissors and pins.