Our coasters are made using a dye-sublimation process. The inks are infused directly into the surface of the tiles using high temperature and pressure, resulting in vibrant colors. The hi-gloss finish is waterproof and heatproof and has a cork base. Each coaster measures 4.25″ x 4.25″. In addition, if you would like a special set of four different coasters, please request a custom order of any four in our store at NO EXTRA CHARGE.