These magical colour-changing mugs start off black and once filled with hot water slowly reveal a hidden message beneath. Wow your coffee- and tea-loving friends with this great novelty item 
(N.B. The slogan/picture beneath is very slightly visible without hot liquid inside) 
This factory-produced 11oz mug is exclusively manufactured for JNR and features a copyrighted design, protected by The Registered Designs Act 1949 
This high-quality printed mug is dishwasher-safe and microwave-proof 
Carefully packed into a polystyrene shell to prevent damage in transport and boxed in a specially-printed gift cardboard outer sleeve box 
This design is also available on men's loose-fit and lady-fit t-shirts, as well as a hoodie (hooded top), a sweatshirt and a gigantic 2-litre (70oz) mug, so please search the title within our store