The laser engraving of organic materials like wood is based on material carbonisation which produces darkening of the surface and marks with high contrast. Directly “burning” images on wood were some of the first uses of engraving lasers. Hardwoods like walnut, mahogany and maple produce good results. Softwoods can be judiciously engraved but tend to vaporize at less-consistent depths. Marking softwood requires the lowest power levels and enables the fastest cut speeds, while active cooling  inhibits ignition.