Towards a Sustainable Preservation of Medieval Colors through the Identification of the Binding Media, the Medieval Tempera

Medieval colors used in illuminated manuscripts from the 12th to 15th centuries can be at risk. Knowing the binding media used, the medieval tempera, is fundamental to developing new and greener methodologies to increase sustainability in Cultural Heritage. A closer look at the tempera used in medieval illuminated manuscripts kept in Portuguese collections, namely, the Ajuda Songbook (13th c.), the winter breviary (14th to 15th c.), the books of hours (15th c.), and a Renaissance Charter (1512), shows that most of the paints analyzed used a tempera similar to gum mesquite. Infrared spectra were the basis for the differentiation between the gums used in medieval times originating from Prosopis spp. and Senegalia spp., gum mesquite and gum arabic, respectively. The ethnobotanical uses of gum mesquite further engage the reader. This micro review represents a significant step forward in Heritage Conservation, offering new perspectives for innovative and greener treatments. Our research, focusing on the differentiation of gums used in medieval times and the identification of the binding media, has the potential to revolutionize our understanding and the preservation of illuminated manuscripts in Cultural Heritage.