If you are going to sew them with a machine, use a denim or leather needle right next to the satin stich edging. If it has the iron on gunk on the back it will break your needle if you try to sew through it. If you want to just iron them on the quilt and they don't have the iron on gunk already, use the heavy duty double sided pellon it seems to work best. Put it on the patch first then iron the patch on the quilt top.
Old Girl Scout Leader.