Perhaps most relevant to this current paper is a 2020 study in which scientists analyzed the platform screamWhich was showing worrying signs of decline. He concluded that the damage was not the result of exposure to light, but rather moisture – specifically, from the breath of museum visitors, perhaps as they leaned in to get a closer look at the master’s brushstrokes.
let there be (x-ray) light
Co-author Letizia Monico during experiments at the European Synchrotron.
ESRF
Co-author Letizia Monico during experiments at the European Synchrotron.
ESRF
Co-author Annelies Ríos Cassier (University of Antwerp) is carrying out micro-sampling from the green area conspiracy,
vanbirvliet lies
Co-author Annelies Ríos Cassier (University of Antwerp) is carrying out micro-sampling from the green area conspiracy,
vanbirvliet lies
Photomicrographs of paint fragments taken from two altered emerald-green areas conspiracyAnalyzes were performed using vibrational spectroscopy techniques and advanced synchrotron technology methods.
Miliani et al., 2025
Photomicrographs of paint fragments taken from two altered emerald-green areas conspiracyAnalyzes were performed using vibrational spectroscopy techniques and advanced synchrotron technology methods.
Miliani et al., 2025
Co-author Annelies Ríos Cassier (University of Antwerp) is carrying out micro-sampling from the green area conspiracy,
vanbirvliet lies
Photomicrographs of paint fragments taken from two altered emerald-green areas conspiracyAnalyzes were performed using vibrational spectroscopy techniques and advanced synchrotron technology methods.
Miliani et al., 2025
The emerald-green pigment is particularly sensitive to degradation, so the authors of this latest paper decided to analyze this very pigment. “It was already known that emerald-green decays over time, but we wanted to understand precisely the role of light and humidity in this degradation,” said co-author Letizia Monico of the University of Perugia in Italy.
The first step was to collect emerald-green microscopic samples from artwork of that period with a scalpel and stereomicroscope – in this case, conspiracy (1890) by James Ensor, currently housed in the Royal Museum of Fine Arts in Antwerp, Belgium. The team analyzed untreated samples using Fourier transform infrared imaging, then embedded the samples in polyester resin for synchrotron radiation X-ray analysis. They conducted separate analyzes on both commercial and historical samples of emerald-green pigment powder and paint tubes, including one from a museum collection of paint tubes used by the stage.
Next, the authors created their own paint mockups by mixing commercial emerald-green pigment powder and their laboratory-made powder with linseed oil, and then applied the mixture to polycarbonate substrates. He also squeezed paint onto the substrate from stage paint tubes. Once the mockups were dry, thin samples were cut from each mockup and also analyzed with synchrotron radiation. The mockups were then subjected to two aging protocols designed to determine the effects of UV light (to simulate indoor lighting) and humidity on the pigments.
Results: In the mockup, light and humidity trigger different degradation pathways in shades of emerald-green. Moisture results in the formation of arsenolite, making the paint brittle and prone to chipping. Light discolors the color by oxidizing the trivalent arsenic already present in the pigment into pentavalent compounds, forming a thin white layer on the surface. Those findings are consistent with the samples analyzed conspiracyConfirms that degradation is due to photo-oxidation. Light, it turns out, is the greatest threat to that particular painting, and possibly other masterpieces of the same period.
Science Advances, 2025. DOI: 10.1126/sciadv.ady1807 (About DOI).
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