I havent had any issues with mine rubbing off yet. Im almost finished the work on my glock. Before it used to look something along the lines of this.
Recently, after picking up that krylon camo, I sanded my glock down and primed it with krylon primer, after letting it dry, I remove the mag and taped up the lower body in prep for painting the slide. Using nice even gliding sweeps I sprayed on the first coat, after drying I did a light second coat effectively covering any problem spots.
I taped up the majority of the mag except the part that pertrudes from the bottom of the gun and painted that part OD as well.
After the mag and slide were done, I taped up the slide and gave the lower half of the gun a good once over with krylon matt camo black and let it dry, after that I touched it up again with a second coat.
After all was dried, it looked pretty decent and nothing has rubbed off as of yet, sanded, primed, 2 coats.
I think it looks good, Im not entirely finished yet, Im gona pin out the trades and redo them in black and I still have to paint the triger and mag release OD as well, and well of course as per most images posted by me, shameless SG plug.