How do I iron on a patch with a backing so the edges don't curl and it doesn't become stiff?

Localized wear, faded knees, loose pocket stitching-there is no need to rush to discard garments with such minor damage. According to the principles of textile science, the bond strength of iron-on patches depends 70% on the precise matching of heat-press temperature and duration: if the temperature is too low, the hot-melt adhesive fails to activate fully; if it is too high, the adhesive carbonizes and becomes brittle, causing the edges to curl after washing.

For cotton denim, it is recommended to iron at a constant temperature of 130°C–140°C with moderate pressure for 15–20 seconds. Crucially, do not pull or fold the fabric before it has cooled; this step ensures the patch truly fuses into the material.