The Enameler introduces shade both by using coloured glass or by adding pigments towards the glass just before firing. Once the glass melts and flows, it cools into a difficult, smooth coating over the substrate. 'Significantly less is often much more,' suggests Jennifer Verruto, founder and CEO of Blythe Interiors. https://www.watchesworld.com/exploring-the-aesthetics-of-dial-design-and-decoration/