How to Sew a Flat-Felled Seam
Select high quality and adjust playback speed using the controls at the bottom right of the video.
How to sew a flat-felled seam
A flat-felled seam is a strong, clean finish that encloses all raw edges on both sides of the fabric — you can see it on the side seams of jeans and workwear. It’s durable, neat, and gives garments a polished, professional look inside and out.
Step-by-step instructions
-
Sew the first seam
Place your two fabric pieces together with wrong sides facing and sew using a 2 cm (¾″) seam allowance. Sewing wrong sides together at this stage means both seam allowances will end up on the outside, where you can work with them easily.
-
Trim one seam allowance
Trim one side of the seam allowance down to about half its width using scissors or a rotary cutter. This reduces bulk so the folded seam lies flat against the fabric.
-
Fold, press, and wrap
Fold the untrimmed seam allowance in half toward the trimmed edge, press it well with an iron, then fold it again over the trimmed seam allowance to enclose it completely. Press firmly at each fold to keep everything crisp and in position.
-
Pin and topstitch
Pin the folded edge in place to stop it shifting while you sew, then topstitch close to the folded edge all the way along. This final stitch secures the seam and gives a clean, finished look on both sides of the fabric.
Pro tip
Press thoroughly at every step — a well-pressed flat-felled seam is much easier to topstitch accurately and lies completely flat against the garment. For an extra professional touch, use a slightly longer stitch length for the topstitching, which gives the seam that classic, workwear-style finish.
Want to keep building your skills? Browse all our sewing video tutorials.
Ready to start sewing? Discover all our patterns
Need help? Use our live chat or leave us a message — we’ll get back to you as soon as possible.