The iron on patches are a pain in the butt! DH is really hard on pants in various areas. I've gotten the chino-weight patches that have no glue and sew them in. Works much better than the sticky ones. My machine (Viking) also has a 'mending/darning' stitch that works a charm. It makes little tiny stitches over the entire area. With matching thread and taking my time, I must say, it actually turns out pretty well.