Laser yellowing: myth or reality?

Q-switched Nd:YAG lasers operating at 1064 nm have often been held responsible for the yellowing of various substrates during cleaning. Possible causes are the presence of an underlying yellow layer, residues, light scattering and substrate damage, or combinations of these. This article reviews the existing evidence on this subject, and suggests venues for future practice and research. [Copyright &y& Elsevier]