Throughout his incomparable career, Abraham-Louis Breguet viewed the finishing of his movements through the lens of functionality. Yes, they are wondrous to behold, but the motifs he employed were chosen for purpose. For most of his finishes, the principal criterion was impeding oxidation and corrosion.
Thus, for his brass plates and bridges, his consistent style featured fine graining (“grenaillage”). Striking in its understatement and purity, the grenaillage finish served not only Breguet’s anti-oxidation goals, but fit his distaste for artificial decoration. For similar anti-oxidation reasons, he chose a highly polished mirror finish (“ poli mirroir ”) for the steel hammers of his repeaters. The bluing of screws, at first blush seemingly mere decorative color design (which regrettably is the case with some present day manufacturers who blue screws with paint), actually was completely functional as the color was the result of heat treatment done to harden the steel. The aesthetic finishing flourishes that today are the mark of a timepiece of distinction were simply not within the umbrella of his philosophy.
There has been an evolution in the thinking of watchmakers in the nearly two hundred years that have followed Breguet’s lifetime. Strict adherence to an ethic of applying only finishes that have functional properties has been broadened by notions that the beauty of the movement represents a substantial part of the value of fine watch. In turn, the grenaillage finish employed by Breguet in his workshops two centuries ago has been largely displaced by a rich palate of aesthetic finishes that display the talent and craft of the watchmakers who create them. Both business and technical reasons underlie the change in philosophy that has transpired.
Today’s ethic of a full range of finishes bestowed upon the movement, some done for functional reasons, some purely for beauty, is not only thoroughly and inextricably interwoven with quality and value, but has become a celebrated part of watchmaking tradition. For each one of the finish motifs, historically well rooted rules now govern the particular components upon which it may be used, the techniques and tools for creation, and the notions of what is and is not an acceptable final appearance.