I'm toying with working on storebought ceramic tiles in acrylic. I did a very quick Charmander painting (like, 10 minutes, not counting the two minutes of sanding and gesso-ing before) that at least has the right colors. You have to be positive. It's more a materials test than anything. When that dries, it goes in the oven for a long slow bake and probably an overnight cool down. That's supposed to make acrylic more scratch resistant on ceramic. I have doubt.

Acrylic on ceramic tile.