A magic mug, also known as a heat changing mug, transforming mug, or disappearing mug is a mug that changes color when it is filled with a hot liquid. This effect is created by using thermochromic ink.
Magic mugs are often manufactured and sold as memorabilia. For example, a mug may reveal a picture of the town or monument where it was sold, for example the Haunted Mansion/Grim Grinning Ghost Disney cup. [1] They are sometimes given away to promote organizations. Customers can also have their own photographs printed on the mugs. [2]
