How to approach long-term monitoring of chemical dynamics in oil paintings?

Year: 2025

Authors: Duivenvoorden JR., Targowski P., Sylwestrzak M., Iwanicka M., Striova J., Balbas DQ., Chaban A., Fontana R., Rosi F., Sabatini F., Cartechini L., Doherty B., Monico L., Faluweki M., Atkinson P., Cheung CS., Liang HD., Hill JA., Magrini D., Karagiannis G., Amanatiadis S., Hermans JJ., Keune K.

Autors Affiliation: Rijksmuseum, Conservat & Sci Dept, Hobbemastraat 22, NL-1071 ZC Amsterdam, Netherlands; Univ Amsterdam, vant Hoff Inst Mol Sci, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands; Nicolaus Copernicus Univ Torun, Inst Phys, Fac Phys Astron & Informat, Ul Grudziadzka 5, PL-87100 Torun, Poland; Nicolaus Copernicus Univ Torun, Fac Fine Arts, Sienkiewicza 30-32, PL-87100 Torun, Poland; Nat Res Council Italy CNR, Natl Inst Opt INO, Largo Enr Fermi 6, I-50125 Florence, Italy; Nat Res Council Italy CNR, Inst Chem Sci & Technol Giulio Natta, SCITEC, Via Elce Sotto,8, I-06123 Perugia, Italy; Nottingham Trent Univ, Sch Sci & Technol, Nottingham NG11 8NS, England; Nat R es Council Italy CNR, Inst Heritage Sci, ISPC, Via Madonna Piano 10, I-50019 Sesto Fiorentino, Italy; Ormylia Fdn, Ormylia 63071, Ormylia, Greece.

Abstract: Long-term condition monitoring of works of art can provide new insights into object-specific deterioration mechanisms. Detecting change over time allows us to determine whether deterioration is active, to investigate its cause and to establish the efficacy of conservation interventions. However, long-term condition monitoring poses both logistical and technical challenges. To address the latter, a 6-month pilot study using model systems has been performed to investigate the approach to long-term monitoring of chemical dynamic processes in oil paintings. The focus was placed on metal soap protrusions: a condition phenomenon encountered in oil paintings that results from dynamic chemical pigment-binder interactions. Eight portable non- or minimally invasive examination technologies available via the MOLAB facility of IPERION HS were used to detect change in model systems. These model systems were designed to form lead soap protrusions in situ in a short time frame by including reactive components in their stratigraphy, providing changes on a scale more typical of years or decades in real paint systems. Raking light imaging or commercial colorimetry did not provide sufficient resolution for detecting small-scale changes associated with lead soap protrusions. X-radiography with consistent acquisition parameters in combination with a form of automated recognition of protrusions was found to provide a relatively accessible method for monitoring changes in the spatial distribution of protrusions. 3D techniques such as optical coherence tomography and micro-profilometry were found to be suitable for detecting change in lead soap protrusions, provided that they reach sufficient spatial resolution in the plane of a paint layer (<= 20 mu m) and depth (<= 2-3 mu m). Acoustic microscopy was found to provide insufficient spatial resolution for this purpose. More specificity for lead soaps was provided by techniques that couple high resolution 2D or 3D imaging to spectral information, such as micro-profilometry coupled to VIS-NIR spectroscopy. Journal/Review: NPJ HERITAGE SCIENCE

Volume: 13 (1)      Pages from: 24-1  to: 24-15

More Information: JRD would like to thank Jolanda van Iperen for technical support and Francesca Gabrieli and Momoko Okuyama for useful discussions. This research was conducted within IPERION HS Task 5.1 Project 2 funded by the European Union, H2020-INFRAIA-2019-1 under GA 871034.
KeyWords: Soaps
DOI: 10.1038/s40494-025-01583-4