Event: Pizza Talk: "Macroscale multimodal imaging and spectroscopy reveals raw material selection and production technology of Fayum Portraits"

Speaker: Dr. Ioanna Kakoulli, Professor, Department of Materials Science and Engineering, UCLA

Fayum portraits are paintings mainly on wooden support reflecting Greek painting traditions and Egyptian funerary practices. These paintings are naturalistic portraits of the deceased and provide a snapshot of Greek civic life and customs in Egypt during the Ptolemaic and Roman rule. Non-invasive and non-destructive evaluation (NDE) of these portraits from the macro to the molecular length scale using combined imaging and spectroscopic techniques supported label-free fingerprint identification of pigments and binding media revealing raw materials selection, production technology and the operational sequences (chaîne opératoire) of the processes associated with the making of the painting. Results from the analyses integrating hyperspectral cubes in reflectance luminescence and X-ray fluorescence (XRF) and forensic imaging investigations combined with fiber-optic reflectance spectroscopy (FORS) and portable XRF, indicated the use of a variety of natural and synthetic organic, inorganic and composite pigments mixed with melted beeswax in ‘encaustic’ [εγκαυστική] painting technique. The significance of this research is twofold: 1) research has been conducted without the need to take any samples and 2) results from the analyses revealed key information on the fashion and practices in Egypt during the Greek and Roman period. For example, the production of the green pigment, a synthetic organic-inorganic complex, giving the green color to the ‘gemstones’ of the necklaces in women’s portraits, is similar to the processes in alchemical manuals of the third century AD, describing a method how to color rock-crystals green, in imitation of precious stones. Similarly, the pigment madder lake used to paint the red-purple garments in the portraits replicates technology employed for the production of mordanted dyes to tint yarns for the textile ‘industry’. These results further illustrate the close affinities and interconnections between the various ‘chemical arts’, such as mining, metallurgy, corrosion and dyeing, to the art of painting and how the cultural and socio-political milieu in Egypt during the Greek and Roman period, with philosophies driving experimentation, influenced material choices and processes involved for the production and use of pigments in art.