3. Examination methods

Examination methods begin with macroscopic observations, carried out by illuminating the work in the visible range, possibly by adjusting the angle of incidence of the light on the object, or by using radiation of various wavelengths, in order to reveal information not detectable under simple illumination in the visible range [4] . Once these macroscopic observations have been made, the works and/or samples are often then observed on a submillimeter scale (under a binocular loupe or microscope), or even on a micrometer scale (scanning electron microscopy), or even on a nanoscopic scale (transmission electron microscopy).