Enjoy your morning coffee 21c-style with this artfully simple mug by Louisville Stoneware. Designed exclusively for Proof on Main and found in every 21c guest room, the 10-oz. mug is handcrafted in black clay with either a glazed tulip-color interior, light blue interior, light green interior, or a cantaloupe interior. Louisville Stoneware is one of the oldest stoneware manufacturers in the U.S. and a revered Louisville tradition. Microwave and dishwasher safe.