Investigating the materials used in eighteenth-century tapestries from the three French Royal Manufactories: inputs of hyperspectral approaches
IRAMAT-CRP2A- UMR 5060 CNRS, University Bordeaux Montaigne, Pessac, France
2 Institut des Sciences Moléculaires- UMR 5255 CNRS, University of Bordeaux, Talence, France
Accepted: 15 November 2021
Published online: 30 November 2021
At the end of the seventeenth century, three “Royal” tapestry Manufactories existed thanks to Louis XIV’s first minister, Jean-Baptiste Colbert: Aubusson, Gobelins and Beauvais. This newly acquired title gave rise to the establishment of numerous rules concerning the quality of the materials used for the production of tapestries. These quality standards were ensured by inspectors of the Crown and renowned cartoon painters sent to work in the Manufactories, which led to the birth of the so-called Tapisseries de Grand Teint. To facilitate the study of these high-quality tapestries, a colour chart consisting of more than 600 references based upon formulations from eighteenth-century treatises was created including spectra recorded with two hyperspectral cameras, in the visible–near infrared and short-wave infrared ranges. This reference database was then used in comparison with the spectra recorded in situ on the three tapestries included in the present study. Ultimately, this method allows for the identification of the specific materials used for tapestry fabrication. This paper presents the results of a comparative analysis of tapestries produced in each of the three Royal Manufactories through the use of two distinct and widely used approaches (i.e. through external and internal databases). The first approach relies upon comparisons with an external database via the Spectral Angle Mapper for the classification and mapping of the tapestry materials. The second method classifies the data by first extracting endmembers (reference spectra of pure materials) directly from the tapestry and then creating an internal database using the ENVI-Spectral Hourglass Wizard. This study emphasises the efficiency of each method as well as noting their limitations due to the specificities of the materials studied in the identification of tapestry textiles and dyes. The investigations revealed, for example, differences between the Manufactories in how different textiles were used in the production of tapestries. This comparison thus sheds light on the technical and aesthetic choices of the Manufactories and how they differ.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021