The Enameler introduces coloration both by utilizing coloured glass or by incorporating pigments for the glass just before firing. Once the glass melts and flows, it cools into a hard, clean coating more than the substrate. Encapsulating this Wonderful dial is a 38mm 18K yellow gold circumstance with 10.7mm thickness, https://www.watchesworld.com/exploring-the-aesthetics-of-dial-design-and-decoration/