craftgrrl | Coffee Mugs

Ok here's my first 'actual' post (Hi!). I have a bunch of off-white, plain looking coffee mugs and was thinking that maybe I can do something to them to sort of spice them up a little. My concern is that the mugs already have the gloss shine to it so I'm afraid that if I paint stuff on it, it'll come off the next time I wash them. Is there something I put over the paint so that it sticks? Possibly Mod Podge?