There are a few requirements that need to be met to do relief-carving with the laser. The first is having a CO2 laser that is capable of varying raster power based on grayscale color value and the software in the print driver that controls this. Secondly, a specialized drawing where grayscale color value represents depth is required. Finally, good results won’t be possible without an appropriate carving material, like hardwoods or thick, opaque cast acrylic.
-Jim Puentes, COOLaserCraft