Non-invasive techniques for characterizing the pigments applied on wall houses from Roman Apulum (Romania)

In the past 136 years, numerous archaeological finds have enriched the history of Roman Apulum and Roman Province Dacia with new data. Various pieces were described and analyzed from a stylistic point of view, but they were not investigated in terms of non-invasive analytical techniques to elucidate the painting techniques and the materials used. In this context, this study aims to identify and characterize the pigments used by Roman painters/craftsmen in decorating houses using Apulum and the painting technique. To achieve this goal, fragments of Roman wall paintings recently discovered in three different archaeological excavations from the ancient Roman Apulum were selected and studied using non-invasive analytical techniques (optical microscopy and vibrational spectroscopy). They have various colors and shades, such as red, green, blue, white, yellow, and admixtures. To establish the potential materials used for wall painting, the samples were analyzed by microFourier-transform infrared spectroscopy.