Inseam pockets are sewn into the side seam before the legs are closed
An inseam pocket is a pocket bag stitched to the front and back pattern pieces before you sew the side seams together. The opening sits along the side seam of the garment, hidden in the fold. Unlike patch pockets that sit on top of fabric, inseam pockets are built into the structure, so they're stronger and look cleaner from the outside.
The basic method is the same whether you're sewing pants, skirts, or shorts: you attach pocket bags to the front and back pieces, then sew the side seam closed so the pocket opening is caught in that seam. The pocket bag itself becomes the lining of the pocket.
This technique requires accurate cutting and stitching, but once you understand the sequence, it's faster than hand-finishing a patch pocket and produces a more professional result.
Key Takeaways
- Pocket bags are sewn to the front and back pattern pieces separately before the side seam is closed.
- The pocket opening is created by leaving a gap in the side seam; the opening length is marked on your pattern.
- Pocket bags should be cut from lining fabric or a lighter weight cotton to reduce bulk at the side seam.
- Backstitching at the start and end of the pocket opening prevents the seam from unraveling when the garment is worn.
- Pressing the pocket bag away from the garment after stitching helps it sit flat and prevents puckering along the side seam.
Cut pocket bags from your pattern or a template
Most commercial patterns include a pocket bag piece. If yours does, cut two bags from lining fabric or a lightweight cotton—one for the front and one for the back. If you're drafting your own pocket, the bag should extend from the pocket opening down to about 6 to 8 inches below the hip, and across about 5 to 6 inches wide. The exact size depends on how deep you want the pocket to be.
Pocket bags are usually cut on the grain line to prevent stretching. Mark the pocket opening on both the front and back pattern pieces before you remove the pattern—this is where the side seam will be interrupted. The opening is typically 5 to 7 inches long, positioned roughly 2 to 3 inches below the waistband on pants or skirts.
If your pattern doesn't include a pocket bag template, you can trace the opening onto a piece of paper, then extend it downward and outward to create a bag shape. Keep the top edge (the opening) straight and parallel to the grain.
Attach the front pocket bag to the front piece
Place the front pocket bag right sides together with the front garment piece, aligning the top edge of the bag with the marked pocket opening on the front. Pin along the opening line. Sew with a straight stitch, using a 5/8-inch seam allowance (or whatever your pattern specifies). Start and end with a backstitch to lock the stitches.
After stitching, press the pocket bag away from the garment piece, toward the side seam. This step is important: it prevents the bag from rolling toward the garment and creating a visible ridge along the opening. Trim the seam allowance on the pocket bag to 1/4 inch if it's bulky, but leave the garment seam allowance at 5/8 inch.
Repeat this process with the back pocket bag and the back garment piece. Both bags are now attached, but the side seam is not yet closed.
Close the side seam and trap the pocket opening
Fold the garment right sides together along the side seam, matching the inseam or outseam as your pattern directs. The pocket bags will be sandwiched between the front and back pieces. Pin the side seam from the waistband down to the start of the pocket opening, then pin again from the end of the pocket opening down to the hem.
Sew the side seam in two sections: stitch from the waistband to the pocket opening, backstitch at the end, then lift the presser foot and move to the other side of the opening. Backstitch again, then sew from that point to the hem. This creates a gap in the side seam—the pocket opening—while keeping the pocket bags anchored inside.
The two pocket bags are now connected at the bottom and sides, forming a pouch. The opening in the side seam is where your hand enters the pocket.
Finish the pocket bag edges to prevent fraying
The raw edges of the pocket bag (the bottom and the side edges where the two bags meet) should be finished so they don't fray during wear and washing. You can use a zigzag stitch, a serger, or a binding stitch, depending on your machine and fabric weight.
Trim the seam allowances on the pocket bag to 1/2 inch, then zigzag or serge the edges together. This keeps the bag from coming apart and reduces bulk. If your fabric is very lightweight, you can fold the edges under and stitch them down by hand, but a machine finish is faster and holds up better.
Some sewers prefer to sew the two pocket bags together before attaching them to the garment pieces, creating a finished pouch first. This method works too, but it requires more precision in positioning and is harder to adjust if the bags shift during stitching.
Reinforce the pocket opening corners to prevent tearing
The corners where the pocket opening meets the side seam experience stress every time you reach into the pocket. Reinforce these points by stitching a small triangle or box at each corner. After you've sewn the side seams, go back and stitch a small box (about 1/2 inch square) at the top and bottom of the pocket opening, using a short stitch length.
This extra stitching locks the seam and prevents the opening from tearing or unraveling. Some patterns mark these reinforcement points; if yours doesn't, position them just inside the pocket opening at the corners where the opening meets the side seam.
Alternatively, you can use a bar tack (a series of short stitches in one spot) at each corner. Most modern machines have a bar tack stitch built in, or you can create one by stitching back and forth over the same line four or five times.
Press the finished pocket to set the seams
After all stitching is complete, press the side seam flat with a warm iron. This sets the stitches and helps the pocket bag lie smoothly inside the garment. Press from the inside first, then from the outside, using a pressing cloth if your fabric is delicate or prone to shine.
Pay special attention to the pocket opening: press it so the opening lies flat and the edges don't curl. If the pocket bag is visible from the outside (a puckering or ridge along the side seam), you may need to adjust the seam allowance or repress with more heat and pressure.
Once pressed, try on the garment and reach into the pocket to make sure it's comfortable and the opening is in the right position. If the pocket bag twists or bunches, you can hand-stitch it to the side seam at a few points to anchor it.
Frequently Asked Questions
What fabric should I use for pocket bags?
Use lining fabric, cotton lawn, or a lightweight cotton that matches or complements your garment. Avoid heavy fabrics like denim or canvas, which create bulk at the side seam. If your garment is a knit, use a knit-compatible lining so the pocket moves with the fabric.
Can I add inseam pockets to a garment that doesn't have them?
Yes, but it requires opening the side seam and re-cutting the front and back pieces to include the pocket opening. This is easier on a muslin test garment than on a finished piece. You'll need to unpick the side seam, attach the pocket bags, and re-sew the side seam with the pocket opening trapped inside.
Why is my pocket puckering along the side seam?
Puckering usually means the pocket bag is too thick or the seam allowance wasn't pressed away from the garment. Try trimming the pocket bag seam allowance to 1/4 inch and pressing it firmly away from the garment. If the garment fabric itself is puckering, you may have stretched the fabric while sewing; use a walking foot or tissue paper under the presser foot on your next attempt.
How deep should inseam pockets be?
Most functional pockets are 6 to 8 inches deep, measured from the opening downward. Shallower pockets (4 to 5 inches) work for lightweight garments or when you want a sleeker look, but they may not hold much. Deeper pockets (9 to 10 inches) are useful for pants but can add bulk if the fabric is heavy.
Do I need to topstitch around the pocket opening?
Topstitching is optional and mostly decorative. If your pattern includes topstitching on the side seam, you can stitch around the pocket opening as part of that line. It adds a finished look and can help stabilize the opening, but it's not necessary for function.