guil·loche e·na·mel | gi-ˈlōsh i-ˈna-məl
A form of enamel work, achieved by working the metal on an engine-turned lathe to form a pattern, before enameling over the pattern
Guilloche enamel is a form of work that involves using the lathe to work the metal into a pattern and then enameling over that pattern. Dating back to the 17th century and the “rose machine” processes of the era, it was later popularized in the Victorian Era, and has been applied to other materials including paper money and some toys. Guilloche is most commonly used in jewelry to decorate watch faces, and to enamel brooches and pendants. The result of the guilloche application is a colorful hue augmented by the clear enamel placed over the engraved surfaces.