Commonly, guilloché is thought to be a type of enameling when actually it refers to a specific enameling process.
The word guilloché is French in origin and means “engine turning”. Guilloché in terms of pocket watches or other jewelry refers to an ornamental engine turning pattern. Guilloché patterns are also used in neoclassic architecture and on banknotes to deter forgery. For pocket watches, guilloché involves carving an intersecting and curvy line design into the base metal. Once created, the pattern is filled with different colors and opacities of enamel paint.
The machines used to create guilloché designs, like on the above pocket watch, are no longer produced. Very few modern-day watch manufacturers practice the art of guilloché. Those that do mostly use guilloché only in luxury watches. Various antique and vintage jewelry and vanity items used the guilloché technique including compacts, dresser sets, and charms.
After enameling, sometimes decorative accents such as hand-painted details or embedding diamonds or pearls in a pattern or image were added.
Modern day reproduction guilloché seem to resemble antique guilloché; however only very few modern watch manufactures produce true guilloché watches. While attractive, always verify watches are true guilloché item. It takes time and skill to produce guilloché and the price of real antique or vintage guilloché show that skill.