A laser engraving machine acts as a chisel and fires a pinpoint laser beam on a substrate. The beam exposes the substrate to intense heat. This implies that the laser itself does not touch matter. It is the heat generated by the laser which does the job.
Depending on the duration of the laser’s exposure, the area in the substrate that is targeted by the laser burns or evaporates, or the colour of the substrate changes and creates contrast. When cold, the engraved result is permanent, cannot be erased, and is very resistant to wear and tear.