Non-invasive analysis of mural paintings from a Republican house from 1st B.C. in Ostia

This paper is a comprehensive analytical study of the murals belonging to an ancient Roman house through the
characterization of materials. The project focuses on the wall paintings of the Domus dei bucranes, a house of
the end of the Republican era discovered on the site of the Schola of Trajan in Ostia. This Domus has undergone
several phases of development in the 1st century BC before being destroyed around 20 BC. A new house was
immediately rebuilt after a major change from the ground, which allowed exceptional preservation of the
decoration system. The results complement our knowledge of Roman painting techniques during the 1st century
BC and also provide a comprehensive multidisciplinary approach to the problem of conservation of wall
paintings. These two related objectives have been studied using non-destructive testing methods (MA-XRF,
FTIR and Raman spectroscopy). The analyzes have been performed in situ using our mobile systems. The
different set-ups had to be modified in order to be able to work on horizontal surfaces, specially our XRF
scanner. The study of the pictorial layers address various issues in the field of archaeology: what technique has
been implemented? Does the same technique was used in both phases of the development of Domus? Do they
correspond to the techniques described by ancient writers? These responses are compared to those observed in
other sets of murals dating from the 1st century BC.