craftgrrl | Heat-resistant paint for plastic?

So I have a set of eight plastic (melamine?) plates that I want to decorate.

The plastic is clear, so I'm not worried about the paint being food-safe--I'm just going to paint on the underside and let the colors show through. :)

The plates are microwave and dishwasher safe and I'd love to be able to paint them and still be able to stick them in the wash/microwave. Any suggestions?

Here's an unrelated thing I made so this won't be a text-only post:

So my boyfriend's parents just love giving me clothes. It's really sweet, they're usually like "Hey, I bought this and it doesn't fit/I decided I don't want it and rather than returning it HERE YOU GO!" This fleece pullover was plain and blue and now it is less plain and more DINO-RIFFIC.