We are getting ready for a small social gathering at our place involving cold drinks and festive times, and our hope is to give everyone an insulated mug as a souvenir - you know, the kind that you freeze and then pour your beverage into. What we want to do is put some kind of personalization on the side of the mugs, like their names, the occasion, something like that. But what would you use for such decoration? It would have to be resistant to freezing, and not fall off or wipe off on your hand when the mug got wet. Colored glues seem unlikely, but paints even more so. Anyone ever done this kind of thing, or have any suggestion to offer as to what might work?
You can buy paints at Michael’s or any other craft conglomerate type store that are specifically made for painting on glass or on plastic. As an added bonus, some of those paints are available in pen form or in writing-tipped squeezy bottles - no brushes needed!
You will, unfortunately, have to walk through many aisles of miscellaneous craft stuff to find them, or find a sales associate who looks like he or she might have a clue. It’s my experience that even big-chain craft stores are all arranged differently. And since I’ve never specifically done what you’re planning, I can’t give you a product name - sorry.
Good luck and have fun!
Ya can’t go wrong with plaid paint!
Err…for the non-crafty types, it should be noted that Plaid is a brand name, not a color choice. (And I do believe they are indeed the manufacturers of the plastic paint I was thinking of.)
My experience is that every paint comes off eventually. Even glass paint, the sort you bake on, wears off. It lasts longer than anything you’ll find for plastic, though. To extend the life of paint on plastic, give a thought to a clear coat, once you’ve applied your design. Different brands, different instructions, so YMMV. Good luck, it sounds like fun project.
First, measure your square footage and figure 350-400 SF per gallon. I’d recommend semi-gloss for the bathroom . . .
What?
Oh.
Tripler
Um, never mind. 
Perhaps an ‘outdoor’ paint would be best. It should readily withstand freezing temps and the heat of a dishwasher.
Good luck!
NO!
This one I know won’t. Exterior paint isn’t made for the high temperature washing of a dishwasher. It doesn’t have the binders. Especially on a mug. I doubt it would hold.
Better off with some sort of craft paint specifically made for tableware.
Tripler
Oil based enamel in your filter? Ick.