Interpreting medieval paints through lac dye reconstructions using synchrotron UV-VIS luminescence spectral imaging...

Advancing the study, conservation, and interpretation of medieval manuscripts requires innovative techniques to investigate and reproduce the materials used in these works. One such material is lac dye, a natural pigment vital to the brightness and color saturation of medieval illuminated manuscripts. In this study, historically accurate lac dye paints were reconstructed according to the Strasbourg, Ibn Bādīs, and Mappae Clavicula medieval treatises. Reference samples and the reconstructed paints were analyzed first using innovative methods and then through advanced synchrotron spectroscopy techniques, an approach rarely applied to cultural heritage research. Valuable results were obtained from synchrotron analyses, including maps from imaging in the ultraviolet and in the mid- and far-infrared spectral ranges. The use of chemometrics (principal component analysis) provided additional analytical depth. Data from the SOLEIL synchrotron facility, which combines molecular fluorescence mapping and vibrational spectromicroscopy, demonstrates the potential of synchrotron-based techniques for analyzing reference samples and historically accurate reproductions of medieval paints, enabling precise and reliable comparison of results.