The heat-sensitive photograph mugs are phenomenal 'magic' fun. The heat change mug will highlight Om Sai Ram Text with the yellow background, underneath a black heat change coating. The heat change mug coating 'vanishes' when the mug is hot to uncover Om Sai Ram text (which will wow everybody obviously!). On account of the heat change delicate coating, we suggest you hand wash this heat changing 'magic mugs'.