Attaching a patch is a common way to repair or decorate clothing. Sewing, SEW-on, and iron-on patches are all methods of attaching a patch. Sewing requires thread and a needle to stitch the patch onto the fabric. SEW-on patches have adhesive on the back that can be activated with heat or water. Iron-on patches have adhesive on the back that is activated with an iron. All three methods are effective ways to attach a patch.