Laser marking has emerged as a viable solution for diverse packaging applications over the last several decades. The vast majority of the uses are nonaesthetic, such as marking lot numbers on electrical and automotive parts that enable the manufacturer to monitor their progress through the assembly line and to track their ultimate performance. Some marking applications, however, are targeting the consumer. The undercap markings on linerless closures and high-contrast characters on computer keyboards and on the buttons inside an automobile are notable examples, and more will likely emerge in the near term.Materials from plastics and ceramics to glass and metals can accept a laser mark in some form. The problem for the designer of a marking system is to select the best laser wavelength and optical system for the particular substrate and desired mark…