Let Out Seams

What you will learn

• Measuring seam allowance
• Unpicking a seam
• Re-sewing within the allowance

Materials and tools

• Garment
• Seam ripper
• Pins
• Chalk
• Seam gauge
• Matching thread
• Sewing machine or hand-sewing needle
• Iron and board
• Pressing cloth

Before you start

• Turn the garment inside out and measure the seam allowance with a seam gauge at several points.

1. Find the seam allowance. Measure from the stitching to the raw edge at several points. You can release only the allowance, and you should always leave about 1/4 in (6 mm) at the raw edge. Moving the stitch line out by an amount gains twice that amount at that seam, since the seam has two layers.

2. Work out the gain. A seam allowance of 5/8 in (16 mm) that is let out to 1/4 in (6 mm) releases 3/8 in (10 mm) from each layer, which gains about 3/4 in (19 mm) at that seam. Two side seams give about 1 1/2 in (38 mm) overall.
3. Try on the garment and work out how much extra room you need, for example by measuring how far a fastening fails to meet. If the seam allowance is smaller than the gain you need, stop. The garment cannot be let out enough.
4. Mark the new seam line in the seam allowance, between the old line and the raw edge. Pin it, then baste along it by hand with small, firm running stitches. Leave the old stitching in place for now.
5. Unpick the old stitching along the length you are changing. Cut one stitch at a time with the seam ripper and pull the thread out. The basting now holds the seam.
6. Press the seam flat, using the heat for the fabric. Steam may help soften the old crease. Test on a hidden spot first.
7. Try on the garment. Look for old stitch holes or crease lines. They are sometimes visible and may not press out. Decide whether you can accept them.
8. If the fit is right, sew the new seam with a 2.5 mm stitch length, backstitching at each end. Taper the new line back to the old line at the ends.
9. Finish the raw edges with zigzag or overcasting, since the narrower allowance frays more easily. Press the seam open.

Tips for a neat result

• Leave the old seam alone if the stitch holes are likely to show. Consider instead a different style of change.
• Let out each side equally for balanced fit.

Common mistakes and fixes

Check your result

• The garment is more comfortable and no seam is strained.
• No stitch holes or crease marks show, or they are acceptable.

Projects that use this