You can also apply duracoat with a Preval Sprayer. It is basically a jar and sprayer that makes it into a spray can. Here in the US they are available at Home Depot and other DIY stores for about $5.00 each.
The Duracoat is really nice, and is basically a spray on epoxy finish. It cures with time and when it does, it doesn't rub off. It is expensive, however, so make sure that it is the route you want to go before buying it.
I wrote this in response to someone's question on Airsoftforum: