Our 11 oz. Blue Color Changing Mugs provide a fun and unique way to greet the morning. Our color changing mugs are heat sensitive and actually transistion colors to display your image when exposed to hot liquid. When the mug is cold, it appears blue, but when coffee (or other hot liquids) are added, the blue color magically reveals your chosen image. Most chosen images will not be completely hidden and will have an overall blue cast. These mugs make great novelty gifts for any occasion. These mugs come in cases of 36 pieces.