Get your hands on our exclusive Phi Mu coffee mug, featuring a unique and stunning watercolor design! Start your morning off right sipping from this gorgeous mug. Officially licensed product. 12oz. Stainless steel inner tank Food grade material, BPA free How are they printed? It's magic basically, but if you want the scientific answer... The process is called Dye Sublimation. Artwork is printed onto a sheet of high-release paper and transferred onto the substrate using heat and pressure. Heat converts the solid dye particles into a gas — known as sublimation — and bonds them to the surface. The dye is absorbed into the material creating a smooth, and machine washable finish.