De Lascaux à Van Gogh : De l’analyse de prélèvements à l’imagerie chimique non-invasive des peintures

From Lascaux to Van Gogh: From the sample analysesto non-invasive chemical imaging of paintingsThe analysis of works of art and archaeologicalobjects aims at determining their exact nature, theprovenance and circulation of raw materials, thetransformation and manufacturing processes aswell as their function und utility. Age determinationand the discrimination of fakes are other importantissues. They all intent to contribute to a betterunderstanding of socio-economical organisationand the cognitive capabilities of former societies.From a physico-chemical point of view, the analyseshave generally been performed on representativesamples that allow the determination of traceelements, minor phases or crystal morphologiesthat are indicative of a special material feature orprocess and allow the establishment of objectivecriteria for answering the archaeological or arthistoricalquestions. Today a new trend goes towardsthe increasing usage of chemical imaging methodsthat provide the advantage of being versatile,sensitive to trace amounts of matter, non-invasive(meaning no sampling is necessary) or at least nondestructive(meaning that the sample taken is keptafter the analysis). These analytical methods havebeen primarily used at synchrotron sources becauseof the brillant light they produce. These experimentsinspired the development of laboratory or evenportable equipment providing capabilities powerfulenough to study art and archaeological objects.Through some case studies the new approachesin this interdisciplinary field of investigation arehighlighted in this paper. These case studies focusmainly on the study of paint matter from Palaeolithicperiods ranging to those of modern times