Hyperspectral imaging for the study of two thirteenth-century Italian miniatures from the Marcadé collection, Treasury of the Saint-Andre Cathedral in Bordeaux, France

Publication Type:

Journal Article

Authors:

Aurélie Mounier; Floréal Daniel;

Source:

Studies in Conservation, Volume 60, Number S1, p.S200-S209 (2015)

Abstract:

Illuminated manuscripts are complex multi-layered and multi-material objects which include a support, preparatory layer, pigment layers, and often highlights. During research into a collection of medieval miniatures (Marcadé collection, Treasury of the Saint-Andre Cathedral in Bordeaux, France) dating from the thirteenth to the sixteenth centuries, two Italian illuminations were studied using hyperspectral imaging. This technique associates reflectance spectra with each pixel of the image. The characteristics of the spectral signal in the visible range are used to map pigments comparing reflectance spectra obtain with those of our reference library of medieval pigments. The exploitation of the data cube of the hyperspectral imaging was completed by point analyses such as Raman and X-ray fluorescence spectroscopy commonly used for the identification of pigments. A methodological development as well as preliminary tests on models made according to medieval recipes and materials (parchments, pigments, and binders, alone and combined together), allowed the validation of the analytical parameters and the development of a database of reference spectra. In the two Italian miniatures, the palette was identified and corresponds to typical medieval pigments as lapis lazuli, red lead, lead white, green copper-based pigment, and probably anthraquinone-based pigments such as brazilwood and kermes. Gold foil gilding decorates the corners of the images.