Art conservation and art restoration are intricate fields requiring a blend of artistic sensitivity and scientific precision. Microspectroscopy has emerged as a revolutionary tool in this domain. It has transformed the way conservators understand and care for artworks, offering insights that were previously impossible to grasp.
Microspectroscopy: A Deep Dive
Spectroscopy, specifically Fourier transform infrared (FTIR) spectroscopy, is a non-destructive method that examines the molecular composition of materials. Microspectroscopy, with its ability to obtain spectra of microscopic samples or sampling areas, has been widely used in art analysis to determine the molecular structures present in paintings. Specifically, it is a valuable tool for the investigation of a painting’s stratigraphic structure, which involves identifying binders, pigments, and other materials used in the preparation layers of artworks. The spectra that are acquired during analysis can be easily identified with the aid of spectral libraries, thus providing a detailed breakdown of the materials present.
Tintoretto’s Stratigraphy: A Case Study
A prime example of microspectroscopy’s prowess in art analysis is the study of a painting sample from Tintoretto’s work at the Scuola Grande di San Rocco in Venice. This sample, a purple veil fragment, was taken from a depiction of a snake and represents Tintoretto’s pictorial technique. The sample was embedded in resin, which revealed four well-defined layers and an ill-defined, fifth layer.
The spectroscopic analysis aimed to identify the composition of each of the five pictorial layers. Key questions included whether the top layer contained oil as a binder; what materials composed the intermediate layers; and what the nature of a particular greenish layer was. Furthermore, the study sought to determine the components of the earth pigments in the ground/preparation layer.
The Power of the FTIR Microscopy
The sample was meticulously analyzed using an FTIR microscope. This state-of-the-art instrument offers precision and agility, making it indispensable in fields ranging from art restoration to pharmaceuticals. The microscope’s objectives, infrared capability, and clear imaging provide a comprehensive view of the sample.
The analysis began with a visual mosaic, followed by a more detailed visual and IR mosaic. Spectra were acquired in ATR mode, ensuring the sample remained undamaged. The resulting visual mosaics provided a clear picture of the regions within the stratigraphy, while the correlation maps evaluated the presence of different materials.
Unraveling Tintoretto’s Secrets
The results were illuminating. A lipidic binder, likely linseed oil, was detected in both the upper pictorial film and the preparation layer. Additionally, proteins, likely animal glue, were found in the ground/preparation layer. This protein was commonly mixed with white lead or earth pigments by Tintoretto to create an ideal optical layer. Furthermore, the presence of azurite, magnesite, malachite, and calcium and magnesium carbonates was identified.
The Revelatory Nature of Microspectroscopy
The analysis of Tintoretto’s stratigraphy underscores the invaluable role of microspectroscopy in art analysis. Not only does it offer a window into the artist’s techniques and material choices, but it also aids in the conservation and restoration of artworks. By understanding the composition of paintings down to their molecular level, conservators can make informed decisions about restoration techniques. Microspectroscopy thus bridges the gap between art and science.
Read the full case study of a Tintoretto stratigraphy with micro-FTIR spectroscopy or explore our microspectroscopy selection guide for more insights into FTIR microscopy and other forms of micro-analysis.
- Case study of a Tintoretto stratigraphy with micro-FTIR spectroscopy
- FTIR Microscope, Research-Grade Microscope
- Learn more about FTIR spectroscopy
The application note involved in this article was authored by: Barbara Bravo (Thermo Fisher Scientific), Francesca Caterina Izzo, Elisabetta Zendri, Eleonora Balliana (Ca’ Foscari University of Venice). The blog article was edited by Mike Bradley. Product Manager, FTIR and FTIR Microscopes (Thermo Fisher Scientific).