A multi-analytical approach for the characterisation of 20th century paintings

A basic rule of thumb in art identification is the employment of scientific techniques as they provide pivotal information on the complex structure of paintings. This research will show how two selected case studies (Mon Amour, attributed to Picasso and Bathing Women, attributed to Munch) allowed to test a methodological approach aimed at the characterisation of a wide variety of materials commonly used in 20th century art. The combined set of analyses consisted of preliminary non-invasive imaging techniques and portable X-ray fluorescence spectroscopy (EDXRF); the second stage of the protocol was the characterisation of the selected samples cross-section by means of Scanning Electron Microscopy (SEM-EDS), Fourier Transform Infrared (FTIR) and Raman microscopy. The material characterisation has allowed to date the two paintings within the lifetime of the supposed artists, due to the presence of synthetic organic compounds as PR3 and PG7. In order to confirm or refuse a compatibility with an artist, the data obtained were correlated with those reported in the literature; but the lack of published data did not allow to compare and evaluate the two specific time spans for authentication purpose. Thus, the following study will propose a best practice for the characterisation of 20th century pigments, discusses challenges in the authentication field and underlines the importance of the sharing of results even for paintings of dubious attribution.