Analysis of brazilian paintings of the 20th century: Suspects and authentics through in situ and Non-Invasive techniques.

This work studied suspicious and authentic artworks by Brazilian painters Ivan Serpa, Ismael Nery, and Iberê Camargo by XRF, FTIR, OM, and MA-XRF techniques. The studies made it possible to verify that all suspicious artworks are counterfeit artifacts. The analyses were conducted in situ, and different approaches were applied for data treatment. For example, principal component analysis and spectral deconvolution were performed on the XRF data. From these methods, it was possible to verify that the suspect artworks by Ivan Serpa and Iberê Camargo have different materiality than the authentic paintings. Additionally, MA-XRF images did not reveal the presence of a polychrome preparation layer in the suspicious paintings by Ivan Serpa. The suspect artworks from Ismael Nery exhibited a Ca-K/Ti-K ratio that indicates they were created on a low-quality paper support, which is not suitable for paintings. The differences in materials used in the suspicious and authentic artworks are further supported by the FTIR and OM results. In addition to the physicochemical analysis, the paintings were studies graphotechnical examinations, financial evaluations, and artistic analyses that demonstrated they were counterfeit artifacts. The results of the analysis demonstrate how physicochemical techniques can contribute to the forensic investigation of paintings. However, this work highlights the importance of applying distinct treatments to the XRF data in order to accentuate the differences between the suspect and authentic artworks.