CIRCULAR GRAINING (PERLAGE)
Circular graining (perlage) is a decorative pattern applied to flat surfaces, typically the bottoms of recesses. It consists of a linear or circular interweaving of discs with concentric lines created by abrasion.
While the external surfaces of a component allow for a wide variety of finishes (e.g., Geneva stripes, satin finishing, etc.), recesses and concave clearances are unsuitable for such decorations. Perlage is ideally suited for these areas and remains the preferred decoration for the recesses of a mainplate or bridge.
Perlage was regularly used during times when the water resistance of watch cases was not as advanced as it is today.
Perlage has the unique characteristic of capturing dust and preventing it from falling into the gear train and escapement.
In high-end watches, the areas of the mainplate and bridges surrounding the gear train are still perlage-decorated, as is the inner surface of case backs. This practice aligns with the original technical utility of perlage from earlier times.
Circular grainging (perlage) can be done by hand with the help of a drilling machine.
The circular graining (perlage) can be done by hand or by machine.
To increase productivity, circular graining (perlage) is done by machine.