Definition
Staystitching is a line of regular stitching sewn through a single layer slightly inside the seam line of a curved or bias edge, to stop it stretching before assembly.
Necklines, armholes, curved waists and other edges cut partly on the bias stretch as soon as you handle them. Staystitch them right after cutting, before any other step, and they keep the exact length the pattern was drafted for, so facings and bindings still fit.
How to do it:
- Use a normal stitch length, about 2 to 2.5 mm, through one layer of fabric.
- Sew about 3 mm (1/8 in) inside the stitching line, in the seam allowance: with a 1.5 cm (5/8 in) allowance, stitch at 1.2 cm (1/2 in) from the edge; with a 1 cm (3/8 in) allowance, at 7 mm (1/4 in).
- Sew directionally, from the high point to the low point: on a neckline, from each shoulder toward the center, so you do not push the fabric out of shape.
- Do not pull the fabric as you go, and do not remove the stitching later. It stays hidden in the seam allowance.
If an edge has already stretched, sew the staystitch with a slightly longer stitch and pull the bobbin thread a little to ease it back to the pattern size.
If a step in your pattern says to staystitch and you are unsure, you can ask the Sewly sewing guide directly, for example "what does staystitch mean?", and get an answer for that step of your pattern (see ask the guide).