Laser marking is the process of directing a laser beam to etch the surface of a porous or nonporous material substrate to provide the contrast for legible characters, graphics, and machine-readable symbols, such as one- and two-dimensional barcodes. Laser marking devices date back to the early 1980s for marking and coding food products and metals. A laser marking system is an assembly of electrical, mechanical, and optical components, which includes a laser. There are many methods for directing the laser beam onto the material substrate to produce a mark. Mask, galvanometric scanning, and acoustic optic are the most common methods used.