I used blackboard paint to add some little panels on these mugs. I used sealer to make them a bit more robust but still writable. I've only painted these tiny panels of blackboard paint and I can't stop thinking about what I want to paint next. I made these mugs to go with a coffee gift certificate which I popped in the envelope you see. An easy gift no? So heed this as a warning, only buy a bottle of blackboard paint if you are prepared for the urge to paint everything.you.see.ever.