For a long time, guilloche was considered to an endangered craft, no longer profitable enough for many in its original form. Only a few individuals are proficient in this type of refining, which was developed more than 300 years ago. The goldsmith school in Pforzheim is one of the last institutions that still train students in using guilloche machines. Guilloche refers to a special pattern or ornament created with several simple, interlaced or overlapping lines. The individual lines form string-like, often asymmetrical, closed ellipses or circular tracks. Engraving guilloches on metal is called ‘to guilloche‘. From the 17th century onwards, guilloche machines – a type of lathe specialized for this purpose – were used. The delicacy and complexity of the design largely depends on the degree of finesse with which the machine is operated.

At the time of its creation, the technology of guilloche was used in particular as a security feature when printing banknotes, bonds, passports, and identity documents, since guilloches on the engraved printing plates used at the time were not easy to reproduce. In the more recent past, guilloches have been used predominantly as an engraving option for watches and jewelry. In contrast to printed guilloche patterns, this also takes the spatial design of the pattern in the material into consideration.

In the last years, a few manufacturers from the jewelry, watch, and writing device industries have rediscovered the art of guilloche. Otto Hutt is one of the few companies that continue to use this challenging technique. The business has not only continued the precision process manually, but also further developed it to include an innovative CNC-control.