Flat-felled seams were the typical choice throughout history for underwear and shirts, for good reasons:
Flat-felled seams are smooth - there's no raw edges or bumpy seams to chafe against the skin.
They're durable - with no raw fabric to fray, they help a garment withstand constant laundering and wear.
These days, well-made shirts still use flat-felled seams, but mostly you'll see them on jeans.
To sew a flat-felled seam:
- Sew the seam as usual.
- Trim away half of one seam allowance.
- Wrap the untrimmed seam around the trimmed one.
- Press flat to the side.
- Stitch through all the layers, close to the fold.
You can learn more about how to make flat-felled seams and more in our Beautiful Seams and Hems class!