Spectroscopy refers to a group of physical methods which decompose radiation according to certain properties such as wavelength, energy, mass, etc. The intensity distribution that can be read is called a spectrum. The quantitative measurement of these spectra is done by means of a spectrometer and, the graphical representation as spectrograms.

Spectroscopy is one of the non-invasive, non-destructive scientific examination methods used in art technology, particularly in the field of damage analysis or forgery detection.

Numerous materials used in works of art, such as inks, pigments, etc., can be identified on the basis of their interactions with electromagnetic radiation. These interactions can be detected and assigned to specific materials; thus, the spectrum becomes material-specific, a quasi-optical fingerprint. Storing such reference spectra in reference databases supports the work of scientists in their research.

For art technological analyses, visible (Vis=visible) light, radiation in the infrared (NIR) and ultraviolet (UV) range, and X-rays in particular are used.