News 
A member of the Acrotec group, the Biel/Bienne-based company unveils a major innovation that transforms a discreet mechanical component into a unique aesthetic and functional feature: the engraved barrel spring. High-precision laser surface treatment technology now makes it possible to decorate the edge of the spring without altering its mechanical properties.
Until now, the mainspring coiled inside the drum was invisible and of no visual interest. Thanks to this patented process, this essential component can now become a design feature or a traceability element visible through a movement’s skeletonised openings or transparent components.
This engraving not only enables a logo, text or pattern to be added, but also creates an evolving visual effect as the spring is wound or unwound, with a dynamic morphological rendering that brings the movement to life. All manner of 3D effects, texture variations, colour or brightness can be achieved by modulating the size of the laser spot and the intensity of the impulses.
In addition to its aesthetic advantages, this process opens up new possibilities for watch customisation (name, date, unique message) and anti-counterfeiting measures. It also enables direct integration of a power-reserve indicator, engraved in a visible or technical manner depending on whether the barrel is open or closed.
Already in development for several Swiss watch brands, this innovation is the subject of a patent application with the Swiss Federal Institute of Intellectual Property. Générale Ressorts is the first company in the world to master this decorative and functional engraving technology on mainsprings, while guaranteeing its industrial reproducibility as of now.
May 28, 2025