iW Magazine iW Summer 2018 | Page 55

GUILLOCHÉ & ENAMEL DIALS The art of guilloché is based on the royal craft of ornamental turnery, prevalent in European royalty from the sixteenth through the eighteenth centuries. Watchmakers invented complex machines for guilloché, and Chronoswiss continues to make dials using a nearly century-old hand-operated rose engine (left) to make classic guilloché patterns for cases, dials, components and rotors. Using only his or her hands, the guilloché artisan moves the dial against the graver tool, which applies the cut from the outside to the inside, engraving the patterns about a tenth of a millimeter into the dial. The individual lines are only about two-tenths of a millimeter, making for very filigreed embellishment.  ENAMEL COATING Hand-cut guilloché dials, already rare in watchmaking, are then accentuated in the Chronoswiss Artist’s Collection. Here, Chronoswiss artisans give the typical guilloché wave pattern extra depth by adding a special enamel coating. After cleaning the enamel, the enameller mixes it with water and applies it to the dial. But even then he or she must be extremely careful to keep the enamel level when being fired. Then, after all the layers have been fired and the dial has been polished, the dial returns to the rose engine for another round of guilloché.  Chronoswiss applies a special Breguet threading, an intricate guilloché border pattern, that really makes the series stand out among its peers. High-fire enameling is essentially pulverized and usually colored glass melted onto metal under high temperatures. The process of high-fire enameling is very time consuming. Multiple firings are required to achieve a perfect color, and each layer is less than one-tenth of a millimeter in height. Before the enamel powder is applied, it needs to be thoroughly cleaned to achieve a perfectly clear and translucent color. Source: Chronoswiss Flying Regulator Night and Day in rose gold The 44mm Chronoswiss Flying Grand Regulator Limited Edition, in steel Flying Regulator Open Gear Anniversary Edition, in red gold SUMMER 2018 | INTERNATIONAL WATCH | 55