Created by applying a coloured, heat sensitive coating to the outside of a Durham ceramic mug, which is then personalised using the dye-sublimation print process. When hot liquid is added, the heat sensitive coating becomes transparent revealing the printed image beneath, strong and bright. As the mug cools, the heat sensitive coating is restored to its original colour.

If the image is printed on a dark coating, it is only faintly visible when the mug is cold. On lighter coatings, the image will be more visible.