Layered pigments and painting technology of the Roman wall paintings of Caesarea Maritima

This study investigated the technological aspects of the Roman wall painting schemes discovered in Caesarea. Remains of painted plaster were found in-situ, attached to their original support. In addition, thousands of loose fragments were excavated. These findings revealed invaluable information about materials and techniques that were in use in the Eastern Mediterranean coast during the Roman period. The diverse painting schemes provide an opportunity to investigate the technology prevalent from the early Roman period (1st century BCE) to the end of the Roman period in that region (3rd century CE). Located at the center of the eastern Mediterranean coast, Caesarea was an extremely important city in the Roman period. The research findings show a strong technological relation to other Roman sites and align well with other technical studies from the region. The study demonstrated the use of local painting materials together with materials that are not local and were therefore imported. All of the paintings were executed on lime-based renders. A range of 9 pigments was identified using optical microscopy and complementary analytical techniques (X-ray diffraction, Fourier Transform Infrared and Raman Spectroscopies, Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy). The pigments that were identified are: lime white; yellow ochre; red ochre; hematite; cinnabar; red lake; green-earth; Egyptian blue; and carbon black. By mixing or layering these pigments, the artists achieved an extended range of coloristic effects. Importantly, the intensive use of the site showed remarkably frequent phases of extensive redecoration, as in the amphitheater and villa.