How to sew French seams
A French seam is sewn twice so the raw edges end up sealed inside. It's ideal for sheer and lightweight fabrics and for anything where the inside shows.
Pinny's tip
For a 0.6 in (1.5 cm) allowance, sew the first pass at about 6mm (1/4 in) and the second at about 9mm (3/8 in). They add up to the full allowance.
For a 0.6 in (1.5 cm) allowance, sew the first pass at about 6mm (1/4 in) and the second at about 9mm (3/8 in). They add up to the full allowance.
What you'll need
- Lightweight woven fabric: French seams get bulky on thick fabric.
- Small sharp scissors: to trim the first seam close.
- Iron: press between each stage.
Step by step
- Put the fabric WRONG sides together (the opposite of a normal seam).
- Sew about 6mm (1/4 in) from the edge.
- Trim the seam allowance down to about 3mm (1/8 in) and press it to one side.
- Fold the fabric along the seam so the right sides are now together, with the first seam right on the fold. Press flat.
- Sew again about 9mm (3/8 in) from the fold, enclosing the raw edges.
- Open out and press the finished seam to one side.
Watch
How to Sew French Seams (1:39)
By Tilly and the Buttons · Open on YouTube
The video this technique page has always pointed to, a 1-minute one from Tilly and the Buttons. Embedded from YouTube with credit; we don't host it. It only loads when you press play.
Common mistakes
- Starting right sides together. You’ll end up with the raw edges outside. Wrong sides first.
- Not trimming enough. Whiskers poke through the finished seam. Trim to about 3mm (1/8 in).
- Using it on curves or thick fabric. Use a bound or overlocked finish there instead.
Watch it done
- How to Sew French Seams by Tilly and the Buttons on YouTube. Opens on YouTube; the video belongs to its creator.
- How to Sew a French Seam | Professional Seam Finish for Delicate Fabrics by Made to Sew on YouTube. Opens on YouTube; the video belongs to its creator.
- How to sew a french seam step-by-step | Sewing Tutorial with Angela Wolf by Craftsy on YouTube. Opens on YouTube; the video belongs to its creator.
Sources
All checked November 1, 2026. We read these; we did not test the products ourselves.