The guilloche interlace pattern, a conventional enriched moulding in classical architecture, may enclose empty space or be rosetted as it is here; the result is a moulding that could be said to be guilloché. Bands of guillloche, picked up from Roman and Renaissance practice, became a widely-used motif of Neoclassicism.
A Guilloché pattern is an ornamental pattern formed of two or more curved bands that interlace to repeat a circular design, most commonly seen on banknotes. These patterns were traditionally used for security printing purposes as a protection against counterfeit and forgery, as well as for decorating valuable objects such as Fabergé eggs and pocket watches.
Guilloché machines (alternately called geometric lathes, rose machines, engine-turners, and cycloidal engines) were first used for a watch casing dated 1624, and consist of myriad gears and settings that can produce many different patterns. In order to create a multifacted visual effect Fabergé engraved the guilloché pattern into the metal surface of their jewelry objects and then applied a coat of clear enamel on top of it.