(This mug is bigger on the inside.)
I have to confess that I'm rather proud of this mug. TARDIS Blue already, I painted a wide strip across the top of the mug to replicate the light-up sign which adorns our favorite Time Lord's ship, and then added a disclaimer to the bottom half in parentheses: This mug is bigger on the inside.
The perfect way to confuse your coworkers, or just generally display your love for the Doctor and his TARDIS.
For Time Lords.
I use heat-set ceramic paint on all my products, which is safe in dishwashers and microwaves. However, using harsh abrasives on the artwork is probably a bad idea.