Add a hot beverage and everyone's clothing disappears. Featuring 13 works of art from the 15th to 20th centuries. 12 oz. mug. Heat changing mugs are microwave safe, but not dishwasher safe. From the Unemployed Philosophers Guild. Don't worry. We are employed, just not as philosophers. We're a small, Brooklyn based company specializing in gifts for the sophisticated gift giver. For whatever you need, we have presents of mind.