Aluminum is often anodized, i.e. provided with a ceramic-like oxide layer to protect the material from abrasion or natural oxidation. The layer also has a decorative character, since it can be anodized in many colors.
CO2 or fiber lasers are suitable for labeling the anodized surface. Classically, the CO2 marking laser creates a bright lettering (by bleaching), while fiber laser systems mark dark as well as bright. In both cases, the effect brought about by the laser is a color change.
In order to obtain a bright inscription, a light-colored lacquer layer lying under the anodized oxide layer or the aluminum itself can also be exposed in the layer removal process, but this also brings the disadvantage of being susceptible to corrosion.
With a high level of application know-how, it is now possible to create bright markings on anodized surfaces even with a fiber laser. This takes place in the color change process, through a kind of fading, leaves the surface intact and creates markings that are permanently resistant. At the same time, you take advantage of the high contour sharpness and filigree character of the fiber laser marks.