CO2 lasers with power levels below 500 W produce energy that is easily absorbed by most organic materials, but is mostly reflected by metals at room temperature. While CO2 lasers can mark, cut and engrave organic materials, marking on metals is only possible using specialized optics or marking compounds.
Below is a list of some materials which can be effectively processed with a CO2 laser in the sub 500 W power range. The list is not exhaustive; many materials not mentioned here can also be processed very effectively with a CO2 laser.
(Source: Universal Laser Systems)