Pigments & dyes in a collection of medieval illuminations (14th-16th century).

The Marcadé Collection (Bordeaux Cathedral treasury) consists among other objects of 42 illuminations (14th to the 16th century) from five origins (France, Italy, Germany, the Netherlands, and Spain). For better knowledge of these miniatures, the pigments and dyes have been analyzed in ten illuminations chosen in order to represent the diversity of the collection. The aim of this study is to establish a panorama of the pigments and techniques used in medieval miniatures through the study of a set of manuscripts and to discuss the potentialities of the analytical techniques in order to reach this objective. Hyperspectral imaging is a rapid, mobile and noninvasive technique. It gives reflectance spectra for each pixel of the image. The datacube obtained was treated in order to visualize images and reflectance spectra. The software allows the mapping of the pigments by comparing spectra with those of our database. As some interpretation difficulties can appear for dyes or mixtures, to confirm the identification, point techniques such as Raman, X-ray spectroscopy, and Fiber Optic Reflectance Spectroscopy in the Near Infrared range were used. Analyses allowed access to the palette for each illumination and showed the colours diversity and pigments treatment. They increase knowledge about the materials used and the evolution of them during the time period: the use of dyes and shell gold became more important at the end of the period. The analytical choice respects the fragility and preciousness of these artworks and helps the fast data acquisition for the materials identification. [ABSTRACT FROM AUTHOR]