Zipper flys are very popular in ready-to-wear (rtw) clothing. They are very easy to install. If you follow these directions, you will construct a fly that no one will know is home sewn.
- Cut your pants fronts.
- Sew any darts or pleats.
- Mark the center front line on your pants pieces; this line is marked on your pattern pieces.
- Sew the fronts together along the center front line. From the bottom of the zipper down, sew with a regular stitch. From the bottom of the zipper and up, use a basting stitch. The point here is to baste your fly shut. A short stitch will make it more difficult to rip out later.
- Place pants fronts on table, wrong side up. Fold both fronts to the left, leaving one fly extension pointing to the right. Pin zipper in place, with side lining up to center front. You will be sewing the side furthest from center front.
- Use a zipper foot to stitch close to the zipper on the side sticking out from the pants fronts.
- Turn zipper over. Fold the extra fabric down under the zipper. The extra fabric may extend under center front. Pin and stitch about 1/8 of an inch (1 mm) from zipper. This holds that extra fabric in place.
- Use zipper foot to stitch close to the zipper.
- Flip pants so that pants fronts are both on your right. They were on the left.
- Turn zipper over. Make sure that it’s flat.
- Pin zipper to the fly extension on your left.
- Using a zipper foot, sew close to the zipper.
- Now your zipper is attached to both fly extensions, but no sewing shows on the front of the pants.
- Turn pants over so they are right side up.
- Butt fly template against the center front seam. If you don’t have a fly template, you can copy one from a pair of pants.
- Trace around fly template.
- Pin pants front to the fly extension underneath. Make sure everything is nice and flat and smooth.
- Using your usual foot, sew fly stitches in place. Note: I always start at the bottom. If I start at the top, I tend to twist the fabric.
- Hey, it looks like a fly!
- Admire your fly.
- Admire your fly some more. But wait; something is missing!
- Cut a piece of fabric 4×8 inches (10 x 20 cm) for the fly shield.
- Fold Fly Shield in half, wrong sides together.
- Do you see the difference between the pressed fly and the unpressed fly in step 24?
- Overlock the edges of the fly shield. Optional, cut off some fabric from the bottom to form a curve. There’s nothing wrong with a rectangular fly shield. If you don’t have a serger, you can overlock with your sewing machine. Use your overlock foot and a zigzag stitch.
- Pin your zipper shield to the extention on the underlap side of the fly.
- Fold your pant fronts off to the side, so that you only sew thru the fly shield and extension.
- After you’ve sewn the side of the shield to the extension, tack down the bottom on the opposite extension. This is optional, but it will keep your fly shield from flopping around.
- Admire your fly shield.
- Admire your fly from the wrong side.
- Admire your fly from the right side.
- Use polyester or nylon zippers. If you use a metal zipper, it is much more difficult to trim to size.
- Don't forget to press as you go. It makes a huge difference in the quality of your work.
Things You'll Need
- Pants pattern with fly
- Pants fabric
- Zipper (7 inch/20 cm)
- Tracing material (e.g. paper) to make your fly template
- Chalk or other fabric marker
- Sewing pins and thread
- Sewing machine
- Serger (optional)