Investigating artworks with light

It is now commonly accepted that the understanding of the original materials composition and their alteration compounds represents an unavoidable step in the valorization and conservation of works of art. Through physical-chemical investigations of artworks, valuable information about their history, technique and conservation, can be obtained. As everyone immediately understand, the traditional analysis methods which need the sample to be obtained and examined in laboratory must be often strictly avoid or, at worst, reduced at minimum due to the consideration that any work of art is a precious and unique object. These considerations have led, in recent years, to develop a non-invasive approach enabled by the use of the light, namely its broadest aspect of electromagnetic radiation, as a probe to investigate the artwork’s materials without any sampling[1]. Among several different spectroscopic instruments, suitable for in-situ non-invasive diagnostic, there are well known techniques daily used by people involved in photochemistry and photophysics, namely steady state and time resolved UV-VIS-NIR spectroscopies both in absorption and emission. These techniques provide very useful information which allow organic[2] and inorganic[3] materials used in artworks production to be studied and identified. Furthermore, detailed knowledge of photochemical properties, obtained with laboratory studies performed on pictorial replicas, can provide valuable information on the degradation pathways which materials undergo and precious instructions on how we should preserve them to the best[4]. Since the only way to preserve the universal beauty of our Cultural Heritage is and will be to approach them in a scientific way, it follows that photochemists and photophysicists can play a useful role in this challenge.