The use of added matrix elements such as chemical assists, colorants and controlled plasma formation as methods to enhance laser conservation of works of art

Abstract Factors such as the use of absorbing dopants, reactive gases and controlled wet chemistry, can all be manipulated to enhance a particular aspect of interaction between the laser and target material in order to improve cleaning results and limit damage to the substrate. This fact offers a tantalizing means of improving the results of laser cleaning in conservation. Further, failure to understand these phenomena can lead to problems even with established treatments. A number of laser cleaning protocols have been reexamined using techniques that enhance one form of laser/target material interaction over another. These techniques include the addition of liquids, alteration of the atmosphere, and alteration of the color of the surface to be removed. The importance of wavelength absorption, plasma formation, chemical bond breaking, and gas expansion will be discussed, and examples of simple processes to improve the cleaning of materials using laser exposure will be described.