Definition
A seam finish is any treatment of a seam allowance's raw edges, such as zigzag, overlock, pinking or binding, that stops fraying and makes the inside neat.
Woven fabrics fray at their cut edges, and unfinished seams can unravel in the wash until they fail. The right finish depends on the fabric, whether the inside will be seen, and the tools you have.
| Finish | Best for | Tools |
|---|---|---|
| Zigzag or overcast stitch | Most wovens | Any sewing machine |
| Overlock | Everything, especially knits | Serger |
| Pinking | Firm wovens, lined garments | Pinking shears |
| Turned and stitched (clean finish) | Light to medium wovens | Sewing machine |
| French seam | Sheers, lightweight fabrics | Sewing machine |
| Flat-felled seam | Denim, shirts, workwear | Sewing machine, felling foot |
| Hong Kong (bound) seam | Unlined jackets, thick fabrics | Bias strips |
Finish seams as you go: either after sewing, with both allowances together, or on each piece before assembly, which is easier for seams that will be pressed open. Knit fabrics do not fray, so their seams often need no finish at all, and any finish you use must stretch.
Enclosed seams, such as French and flat-felled seams, need planning: you choose them before sewing, because they change the order of the steps.
A serger is not required for neat insides; see finishing seams without a serger.