Cultural heritage activities at ID21

The ID21 microscopes are regularly used to study ancient and artistic materials. Analyses can be carried out on almost all kinds of artistic materials, such as paintings, ceramics, glasses, plastics, wood and papyrus. Whatever the technical and methodological approaches, questions commonly tackled can be divided into two main categories: those searching for a better understanding of the past and those aimed at providing an educated projection of the future. More precisely, the analysis of ancient and artistic materials can reveal clues about the manufacturing processes developed over time and cultures and consequently about possible exchanges between civilizations. They can also shed light on degradation mechanisms and can ultimately help to optimize strategies for the preservation and conservation of cultural heritage objects. In this page, we review the most recent applications of ID21 instruments in the field of cultural heritage.

The materials used across history for craft and art evolved in time and space, together with the development of new technologies (being progress in firing technologies, discovery of new elements/minerals, elaboration of chemical syntheses, etc). The physical and chemical characterizations of ancient and artistic matters can thus give clues about physical and chemical processes used during manufacturing practices. This can not only provide information about lost technologies but can also be used to establish chronological and/or geological markers for further dating/ authentication of artworks. In this context, fragments of paintings, glasses and ceramics are regularly studied at ID21. More recently, the ability of the X-ray microscope to image letters and decipher the composition of ink in papyrus has also been exploited. In addition, fragments from pioneer color photographs and varnish on music instruments were studied to reveal secrets about their manufacture.

In parallel with the discovery of lost artistic practices, a large number of works aim at understanding the evolution of these materials with time. Most of the alteration processes, e.g. metal corrosion, involve modification of the redox states of the original material, while the average elemental composition of the bulk material remains unchanged. The alteration processes are usually limited to a highly superficial area,  with typical thickness in the micrometer or even sub micrometer range. Nevertheless, such surface changes can have effects on the objects visual appearance. Probing the oxidation of specific elements and more generally their chemical environments is therefore highly relevant when studying alteration mechanisms. This field is intensively studied at ID21. Indeed, the accessible energy range (2.0–9.2 keV) allows the study of: (i) 3d transition metals, being in pigments, glasses, inks or metals as well; (ii), Cl and S species (e.g. SO₂), which are common exogenous species responsible for degradation and corrosion. In parallel, some experiments focus on modern organic based artistic materials, for which the use of µFTIR microscope provides valuable information.