The fading mug reveals a hidden print when a hot beverage is filled in.
When the coffee is cooling down or the mug is empty the original color appears again; what black magic is this?
Gadget shop Brando sells the fading mug with zodiac sign designs for $18. Brando can also make you a custom fading mug with your logo. Also very cool is the Plasma Mug and the lockable coffee cup.