Researchers from the laboratory Photophysique et photochimie supramoléculaires et macromoléculaires (CNRS/ENS Paris-Saclay), the Institut de recherche de chimie Paris (CNRS/Chimie ParisTech – PSL), the Centre de recherche et de restauration des musées de France (Ministère de la culture), the Louvre Museum, the Laboratoire d’archéologie moléculaire et structurale (CNRS/Sorbonne Université) and the ESRF, the European Synchrotron, have studied a microsample of the preparation layer of the Mona Lisa to shed light on Da Vinci’s painting methods. To get more clues about Da Vinci’s palette and technique, they also analysed several fragments from the Last Supper, another masterpiece by Leonardo.

Within the core team of researchers dedicated to this pilot investigation, there is also Ida Fazlic, an InnovaXN student who is carrying out her PhD working on the analytical chemistry of micro-imaging of industrial and historical paints project, with a collaboration between the ESRF, Akzo Nobel, Rijksmuseum and the University of Amsterdam.

She summarized her contributions, saying:

“This work is strongly related to the topic of my PhD project investigating the short and long-term reactions of driers and binders. By investigating the composition of Mona Lisa and The Last Supper using ID13 XRPD setup we saw the presence of plumbonacrite, which is typically the product of the use of a specific lead drier, namely lead(II) oxide. Additionally, we synthesized model paints according to historical recipes to understand the chemical pathway to the formation of plumbonacrite. It was very interesting and exciting to puzzle all the pieces of information together and propose a hypothesis on Leonardo’s painting techniques and materials.

I was beyond delighted and honored to have contributed to such an important project with all the big, world-renowned expert names in our field, thanks to my Supervisor and the collaborations that she and ESRF foster. It’s not very common that a Ph.D. student as I am, at the very early stage of a scientific career, has the opportunity to participate in such a big research project.”

The team used the techniques of synchrotron radiation high-angular resolution X-ray powder diffraction (SR-HR-XRPD), micro X-ray diffraction (µXRD) and micro Fourier-transform infrared spectroscopy (μ-FTIR) at the ESRF’s ID22, ID13 and ID21 beamlines, respectively. The results show the presence of a very uncommon composition in both the Mona Lisa’s ground layer and the Last Supper’s ground and paint layers.

Image: Artistic impression of the Mona Lisa. Credits: I. Fazlic, M. Cotte & V. Gonzalez.

X-ray and Infrared Microanalyses of Mona Lisa’s Ground Layer and Significance Regarding Leonardo da Vinci’s Palette, Victor Gonzalez*, Gilles Wallez, Elisabeth Ravaud, Myriam Eveno, Ida Fazlic, Tiphaine Fabris, Austin Nevin, Thomas Calligaro, Michel Menu, Vincent Delieuvin, Marine Cotte.J. Am. Chem. Soc. 2023, 145, 42, 23205–23213, Publication Date: October 11, 2023 https://doi.org/10.1021/jacs.3c07000

Text by Chiara Facoetti