Men's Button Fly Boxer Shorts

Men's Boxer Shorts

Men's boxer shorts for knit or stretch cotton fabric, cut from just four pieces, with a cut-on button fly closed by two buttons and a waist gathered on elastic in a turned-down casing.

When To Wear

• As everyday underwear under trousers and jeans.
• As sleep shorts or for lounging at home.

Key Design Features

Silhouette: Loose through the seat and legs, gathered in at the waist.

Length: Short legs, ending at the upper thigh.

Waist: The top edge is turned to the inside and topstitched to form a casing for 2.5 cm elastic; no separate waistband.

Closure: Fly extensions cut in one with both fronts and interfaced; two buttonholes in the left front, a topstitched fly line, a bar tack 2 cm above the bottom of the fly, and the left front stitched over the right for 5 cm below the waist.

Back: Centre back seam, no yoke.

Finishing: Seams pressed and overlocked; hem overlocked, turned up and topstitched, with a twin needle or coverstitch on knits.

Level Of Difficulty

Beginner. Two pattern pieces, straight seams, an elastic casing and a simple cut-on fly with two buttonholes.

Fabric Recommendations

Medium-stretch knit fabric from natural or blended fibres, or cotton woven fabric with added elastane. Knits are sewn with a stretch or narrow zigzag stitch, or on a 3- or 4-thread overlocker.

Additional Supplies

• Lightweight fusible interfacing (optional, for the front fly area)
• Elastic tape, 2.5 cm wide, the length of the waist measurement
• 2 buttons

Cutter’s Must

From Main Fabric:

• Front Half– 2 pieces
• Back Half – 2 pieces

From Fusible Interfacing (optional):

Apply to button placket/fly facing for added structure.

Important Information

Before cutting your fabric:

• Print and lay out pattern pieces to determine yardage.
• Check mirrored pieces, notches, and grainlines.
• For patterned fabrics, align carefully for symmetry.

Assembly Instructions

1. Fuse Interfacing

Reinforce the integrated (cut-on) fly extensions on both the left and right front parts with fusible interfacing.

2. Fly Preparation

Overlock the front center edge and the fly edge separately on both the left and right front parts.

On the right front part, press the fly extension toward the wrong side, 1.5 cm away from the center front line.

Topstitch the pressed edge to the garment along the overlocked edge.

3. Front Center Seam

Stitch the front center seam of the two front parts together, beginning at the marked point.

Press the left front fly extension to the wrong side.

Topstitch the decorative fly stitching along the marked line on the left front part.

Overlock and work the buttonholes along the marked placement.

Lay the left front over the right, matching the center lines.

Sew a short horizontal bartack 2 cm above the bottom of the fly.

Topstitch the left front over the right along the folded fly edge, sewing downward for about 5 cm from the waist edge.

4. Side, Back, and Inseams

Stitch, press open, and overlock the side seams.

Stitch, press open, and overlock the back center seam.

Stitch, press open, and overlock the inseams.

5. Waistline Finish

Overlock the upper edge, press to the wrong side, and topstitch to form a casing, leaving a small opening for the elastic.

Insert elastic through the casing and secure the ends firmly.

6. Hem

Overlock the hem allowance, press to the wrong side, and topstitch.

7. Buttons

Sew buttons corresponding to the buttonholes.