craftgrrl | Marble-related question

My brother plays this game called Go. It's japanese, I believe. If you've seen A Beautiful Mind, it's the game that Russel Crow and his friend would always play with the black and white little beads on a very big gridded board.

I wanted to get my brother a new Go board, but the remainder of my money is needed to invest in a small business venture with a friend.

So I was thinking that maybe I could make him some new beads to use on his board, with pictures to make things more interesting. He loves llamas and sheep and domo-kun. But, I was wondering what I would use to seal the images on.

I know to use silicone sealer when making magnets, but what should I use for a backing? The marbles will be picked up and slammed down repeatedly so I don't want the paper being scratched off.

A last resort big project would be to paint the board onto a cookie sheet and make it magnetized go, but I'd be worried about the marbles sticking to each other.

Any suggestions?