A Multi-Analytical Approach for the Characterization of Painting Materials and Metal Soap Formation in Two Artworks by the Argentinian Painter Antonio Berni

ASTRID BLANCO; ISABEL ALCÁNTARA MILLÁN; VALERIA CAREAGA; GABRIELA SIRACUSANO; MARTA MAIER

MINERALS

MDPI

Lugar: BASILEA; Año: 2023 vol. 13

This work describes the characterization of pigments and ground layers in two paintings by the renowned Argentinian painter Antonio Berni (1905–1981). The studied paintings are “Toledo” and “Figure” from the collection of the Provincial Museum of Fine Arts in Santa Fe (Argentina). To approach this goal, an integrated investigation comprising in situ X-ray fluorescence measure-ments by means of a portable system (pXRF), micro-Raman and FTIR-ATR spectroscopy, and X-ray fluorescence scanning electron microscopy with X-ray microanalysis (SEM–EDS) was car-ried out. The results revealed a chromatic palette with inorganic pigments, such as ultramarine blue, cobalt blue, lead white, zinc white, yellow cadmium, and hydrated chromium oxide (viridi-an), together with a preparation layer consisting of a mixture of earth, lead white, and calcite in “Toledo”. On the other hand, the preparation layer in “Figure” was characterized as lithopone, a mixture of barium sulfate and zinc sulfide. ATR-FTIR-analysis revealed the formation of metallic soaps in both paintings due to the reaction of fatty acids from a drying oil used as a binder with lead and zinc pigments, as confirmed by comparison with the infrared spectra of synthetic lead and zinc soaps. This study contributes to the understanding of Berni’s painting style and the fu-ture restoration of both artworks.Keywords: inorganic pigments; oil paint; metal salts; pXRF; ATR-FTIR; micro-Raman spectrosco-py; SEM-EDS