A vast majority of watches you see on the market come with metal dials. The discs that you see usually start of as thin sheets of the chosen material, then indices are either printed or applied on and sometimes patterns are engraved on the surface to give it an interesting texture.
Enamel dials however are special because what you see on the surface is a material close to glass. And to achieve this, silica crystals have to be applied on the surface of the dial and then heated in an oven at high temperatures. The result however is utterly sublime and more often than not can only be appreciated at its full capacity when you see the watch in person. There is a certain elegance that can’t be replicated by any other material.
There are quite a few styles of enamelling techniques that are still being practised today including: champlevé where deep engravings are made on the base material then enamel is filled into these spaces; cloisonné where the enamel is separated into compartments by thin metal filaments; and the most complicated technique of all, grand feu enamelling which has to be done in layers meaning the artisan has to slowly build the dial layer by layer, precisely controlling the temperature of each successive firing in the oven.