ABSTRACT
Grating surfaces are inherently fine pitch delicate structures that are easily damaged. Since they are also expensive there is ample reason to treat them with care. The single greatest enemy of gratings is the human finger. There is a history of curious customs inspectors who tested with their fingernails for the presence of the grooves listed on the label. More common are fingerprints, so often the result of simple carelessness, and many spectroscopists have felt like calling the police to discover whose print is on the grating. Development of high power lasers has led to a new source of concerns: for the first time light sources can be so intense that they can lead to overheating or even ablation of portions of a grating surface.
