Laser engraving involves removing the material from a solid surface. Due to the very high intensity of the laser, materials including steel, titanium and (almost) all other metals can be vaporised directly. This is made possible due to the high pulse power of the fiber laser (Trotec lasers have up to 10 kW peak power) in combination with a very small laser spot diameter (Trotec ~ 45 μm with the F-160 lens). With this method, text, logos, serial numbers and other contents can be laser engraved into the material. The volume of the material is reduced and its colour is changed. The resulting brown areas consist of metal oxides (or rust), which can be cleaned with a second cleaning cycle using polishing parameters. Laser engraving on stainless steel requires high power, low frequency (which results in high power per pulse) and marking speeds of 250 - 900 mm/sec.