Laser engraving metal is a durable and legible way of marking many metal materials. Different processes are used depending on the type of metal being engraved.
If the metal has been pre-treated or coated the laser will engrave away this top coating to reveal the metal finish below. Different treated metals will produce different effects.
If engraving a non-treated metal, the C02 laser will not mark the surface well. In this case we use the compound marking method. A chemical layer is sprayed onto the metal. When the laser comes in contact with the chemical it is fixed to the material resulting in permanent black marks. See examples.