Historical pigments characterisation by quantitative X-ray fluorescence

Most of the historical paints are mainly constituted by inorganic pigments, either pure or mixed, spread on the surfaces using different binding agents. The knowledge of the exact amount of different constituents of the paint, as well as of the mixing and pictorial techniques, is crucial for a careful program of conservation of polychrome works. Moreover, since the availability of these pigments has been changing through the centuries, their identification and chemical characterisation is useful to acquire or deepen information about the artist and his/her work. This information can also be useful for authentication purposes through relative dating because the identification of one pigment respect to another one can be used as a terminus post quem or ante quem the artwork was realized. In this work, X-ray fluorescence data from historical pigments, both pure and mixed, will be presented, in order to obtain quantitative information on the samples and to extract calibration curves to the aim of evaluating the pigment concentration in unknown mixtures.