Transmission Electron Microscopy and Associated Techniques for Cultural Heritage Science applications

The Centre for Materials Development and Structural Studies – National Centre for Scientific Research (CEMES-CNRS) in Toulouse, France, is equipped with a Transmission Electron Microscopies (TEM) facility, a service that can be used for cultural heritage purposes and which is now part of the services offered to European heritage professionals through E-RIHS. The communication will explain how energy dispersive X-ray spectroscopy and electron energy loss spectroscopy were used at nanoscale for the study of the corrosion inhibitor pigment within the protective coating of historical aircrafts; then how electron diffraction mapping techniques helped understanding the growth of multi-phase structures in brown-glazed chinese ceramics. Preparation of thin TEM lamellae will also be discussed as it presents a real challenge in the field.

Addressing the Challenge of Binder and Glaze Identification in Early Neapolitan Paintings through Mid-SWIR-FT Imaging

The introduction of drying oils into Neapolitan painting during the fifteenth century represents a pivotal moment in the evolution of artistic practice, reflecting the influence of Flemish techniques on local workshops. Understanding this transition requires reliable, non-invasive methods for identifying binding media and reconstructing painting stratigraphies. Within the PRIN SHARING (Scientific Humanistic ARt collection INvestiGation) project, a multi-analytical study was carried out on selected paintings from the Museo e Real Bosco di Capodimonte, focusing on works by Colantonio and artists associated with his workshop. External reflection FT-IR spectroscopy revealed lipidic materials, while proteinaceous binders were identified only through micro-FTIR analyses of cross-sections, highlighting the limitations of current non-invasive approaches.

To overcome these challenges, historically informed mock-ups reproducing the stratigraphies observed in the artworks were investigated using hyperspectral imaging in the SWIR region (1000–2500 nm). This approach distinguished spectral features associated with proteinaceous and lipidic binders while providing information from subsurface paint layers. However, the limited chemical specificity of overtone and combination bands, particularly for surface coatings and glazes, demonstrated the need to extend the investigation to longer wavelengths.

Building on recent advances in infrared imaging, we developed a novel point-scanning mid-SWIR Fourier-transform imaging system that accesses the fundamental vibrational region while remaining suitable for the non-invasive examination of cultural heritage objects. Preliminary results show that combining dispersive SWIR and Fourier-transform mid-infrared imaging improves the characterization of binding media and glazing materials, offering new opportunities for studying the transition from tempera to oil painting and, more broadly, complex painted surfaces.

The Characterization of Raffaello Sanzio’s Painting Materials through the Study of the Historical Stratigraphic Sections preserved in the ICR Archive

The Chemistry and Materials Testing Laboratory Archive of the Istituto Centrale per il Restauro (ICR) preserves more than 8,000 cross-sections prepared over the course of seventy years of activity during the restoration of artworks by some of the most renowned Italian and international masters. Within the framework of a sustainable diagnostic approach, the ICR archive represents an invaluable resource and a highly stimulating repository from which new research projects can emerge.

This presentation will illustrate recent studies conducted on three significant works associated with Raffaello Sanzio (Urbino, 1483 – Rome, 1520), dating from the early stages of his career to the years immediately following his death:

1. The Stendardo della Santissima Trinità
2. La Deposizione, also known as the Pala Baglioni
3. La Madonna della Gatta

Historical cross-sections proved particularly valuable, enabling researchers to expand their knowledge of the materials and techniques employed by Raphael in this masterpiece. Together, these case studies demonstrate how the integration of archival scientific documentation and advanced diagnostic methodologies can significantly enhance our understanding of Raphael’s materials, techniques, and working practices, while promoting a sustainable approach to the study and conservation of cultural heritage.

HyperPICO – Prospective Use of In Situ Coupled Hyperspectral-Lasergrammetry Imaging for Preventive Conservation

The increase in both the intensity and frequency of extreme weather events, together with the significant variations in weather conditions brought about by climate change, is creating an unprecedented and poorly assessed risk to collections, particularly those in castle museums which are exhibited in “open-air” environments. In conjunction with the EPICO programme, which has already led to the development of a statistical method to streamline the number of diagnostic interventions on these collections, there is now a need to develop state-of-the-art tools to enable quantitative in situ analyses : scientific photography remains the simplest solution for documenting appearance but it is not, to a limited extent, quantitative ; physico-chemical analyses would require too many samples, given the increase in the number of interventions. The HyperPICO project aims to develop such a quantitative tool by combining a hyperspectral camera with a LiDAR scanning system to create 4D maps (geometry, VIS-IR reflectance). Two sets of challenges have been identified: on the one hand, instrumental challenges relating to the fusion of heterogeneous data and repositioning over a long timescale; on the other hand, challenges relating to preventive conservation, focusing on the explainability – and even the prediction – of deterioration caused by climate change. This instrumentation is being tested as part of a systematic seasonal acquisition protocol with Palace of Versailles in two rooms subjected to strongly different environmental conditions.