Uncommon compound present in Rembrandt’s The Evening Watch

2023-01-19 15:43:58

17-01-2023

A world staff of scientists from the Rijksmuseum, the CNRS, the ESRF the European Synchrotron, the College of Amsterdam and the College of Antwerp, have found a uncommon lead compound (named lead formate) in Rembrandt’s masterpiece The Evening Watch. This discovery, which is a primary within the historical past of the scientific examine of work, supplies new perception into Seventeenth-century portray method and the conservation historical past of the masterpiece. The examine is printed in Angewandte Chemie – Worldwide version.

The Evening Watch, painted in 1642 and displayed as we speak within the Rijksmuseum Amsterdam (The Netherlands), is one among Rembrandt’s most necessary masterpieces and largest murals. Within the framework of the 2019 Operation Evening Watch, the biggest analysis and conservation challenge ever undertaken for Rembrandt’s masterpiece, a global analysis staff joined forces to review how the portray supplies react chemically and with time.

The staff of scientists mixed multi-scale imaging strategies with a purpose to chemically examine the supplies utilized by Rembrandt in The Evening Watch. A X-ray scanning instrument developed on the College of Antwerp (Belgium) was utilized on to the portray, whereas tiny fragments taken from the portray had been studied with synchrotron micro X-ray probes, on the ESRF, the European Synchrotron (France), and PETRA-III facility (Germany). These two kinds of analyses revealed the presence of an surprising organo-metallic compound: lead formates. This compound had by no means been detected earlier than in historic work: “In work, lead formates have solely been reported as soon as in 2020, however in mannequin work (mock-up, contemporary paints). And there lies the shock: not solely will we uncover lead formates, however we determine them in areas the place there isn’t a lead pigment, white, yellow. We predict that most likely they disappear quick, because of this they weren’t detected in previous grasp work till now”, explains Victor Gonzalez, CNRS researcher on the Supramolecular and Macromolecular Photophysics and Photochemistry (PPSM) laboratory (CNRS/ENS Paris-Saclay) and first writer of the paper.

Crystalline phases distribution obtained through structural imaging on an space of The Evening Watch (1642) by Rembrandt van Rijn (1606-1669). Credit score: Antwerp X-ray Imaging and Spectroscopy Analysis group – College of Antwerp, Belgium.

Why did this one not disappear? For Katrien Keune, head of science at Rijksmuseum and professor on the College of Amsterdam (the Netherlands), this discovering is essential to understanding Rembrandt higher: “In Operation Evening Watch we deal with Rembrandt’s portray method, the situation of the portray and the way we will greatest protect it for future generations. The lead formate offers us priceless new clues concerning the attainable use of lead-based oil paint by Rembrandt and the potential influence of oil-based varnishes from previous conservation remedies, and the advanced chemistry of historic oil work.”

What’s the origin of this compound? Can it present info on Rembrandt’s workshop recipes, or make clear the chemical mechanisms energetic within the layers of previous paint? To reply these questions, the scientists studied fragments taken from The Evening Watch and mannequin samples ready within the laboratory simulating the painter’s formulations.

Ida Fazlić, phD scholar on the ESRF and co-author, through the experiment carried out on the European Synchrotron on tiny paint samples. Credit: ESRF/ S. Candé.

They labored with the speculation that Rembrandt used an natural medium (linseed oil) containing dissolved lead oxide (PbO litharge) to reinforce its siccative properties. “Because of the distinctive analytical efficiency of the ESRF, the world’s brightest synchrotron gentle supply, we may map the presence of formates at a micrometric scale, and comply with their formation over time”, explains Marine Cotte, scientist on the ESRF. The spatial organisation of the compounds on the micro-scale and the dynamics of their formulation made it attainable for the researchers to counsel new hypotheses on the chemical circumstances of their in situ crystallisation in previous paint layers.

“Along with offering info on Rembrandt’s pictorial methods, this analysis opens up new avenues on the reactivity of historic pigments, and due to this fact on the preservation of heritage”, explains Koen Janssens, Professor on the College of Antwerp.

The following step for the staff is to additional examine the origin of those formates and examine if they may additionally originate from previous restoration remedies.

This analysis advantages from a facilitated entry supplied to the historic supplies group to the synchrotron methods on the ESRF, that has been applied with assist from the European Union’s Horizon 2020 analysis and innovation programme beneath grant settlement No 870313, Streamline.