Characterization of multi-layered wall paintings from a Roman domus in Santa Maria Capua Vetere

This paper regards the preliminary characterization of wall paintings sampled in a Roman domus located in the city of Santa Maria Capua Vetere. Despite its history and archaeological remains, there is a lack of scientific studies on Roman materials and techniques adopted in this site. Samples were taken from different walls of the villa. Pigments, binders, and mortars were analyzed by optical and electronic microscopies, vibrational spectroscopies including Fourier transform infrared and micro-Raman imaging, and mass-spectrometry coupled to gas and liquid chromatography. Altogether, the multi-layers preparation, the rich pigments palette (both natural and synthetic ones) and the variety of the organic ligands used (terpenic resins or animal glue) support the hypothesis of a very wealthy owner. The absence of calcite in the pictorial layer and the presence of organic binders clearly indicates an a secco technique.