ALPhANOV developed a laser process to turn shiny metals blacker than black.

Based on femtosecond lasers, the process relies on highly intense laser pulses creating nanostructures at the surface of metals such as stainless steel, gold, etc. These nanostructures act as a photon trap absorbing all the light that falls on it. This results in a deep black coating that can easily be shaped to create various features and patterns with high precision and uniformity.

This process is REACH compliant as it does not rely on the use of harmful chemicals. In fact, the metal surface is not even coated by another material and it does not undergo any chemical changes. It is merely reshaped in a way that it no longer reflects light. Unlike paint, powder coats or anodizing, the coating is of the same chemical nature as the substrate and it is engraved in it so it won't ever flake off.

This process can effectively be used for marking various objects, whether for traceability or decoration, or to increase efficiency of solar panels, infrared or space-borne detectors, and other devices.