The Enameler introduces coloration either by utilizing colored glass or by including pigments towards the glass just before firing. Once the glass melts and flows, it cools into a difficult, easy coating more than the substrate. Encapsulating this lovely dial is actually a 38mm 18K yellow gold scenario with 10.7mm https://www.watchesworld.com/exploring-the-aesthetics-of-dial-design-and-decoration/