Setting: Setting (定型)
A heat treatment that relaxes internal stresses in tape or chain and stabilises length and width. Controlled temperature, moisture and tension reduce shrinkage and skew so the zipper stays flat after washing and sewing. Setting also improves hand feel and colour stability. Under-setting leaves residual stress that shows up as waviness, while over-setting can reduce strength. Shrinkage is verified by laundering samples before bulk delivery.