Technical Study of Painting Materials and Techniques

Material analysis was focused on characterization of original and reconstruction materials, identification of deterioration products, and development of appropriate treatment materials. Non- and minimally invasive techniques have been used to characterize original as well as reconstruction and restoration plasters, identify pigments, binders (where possible), salts, biological growth, and previously applied coatings.

Based on a review of existing literature, visual examination, technical imaging (visual-induced luminescence, IR, UV-Vis), and scientific analysis (optical and polarized light microscopy, ESEM, XRD, XRF, FTIR, GC-MS and pyGC-MS), the team, in collaboration with scientists from the Getty and from external institutions, identified, characterized, and described the materials and techniques used in the execution of the wall paintings from the tablinum as a basis for understanding the original technique and mechanisms of deterioration toward conservation planning.

Diagnostic investigations have been integral to the scientific study since the beginning of the project. Scientific research has included flaking and powdering paint, biogrowth, previous intervention materials, and salts.

The paintings in the tablinum are some of the most celebrated at the site but are suffering extensive deterioration. Therefore, one of the primary studies has been to better understand the flaking and powdering paint of figurative scenes and decorative elements on the wall paintings, a typical condition at the site and in the greater Vesuvian archaeological region.

These wall paintings, uncovered in 1938, show severe deterioration, much of which has occurred since excavation. Working with a number of scientific laboratories, the team has undertaken a comprehensive diagnostic study of the flaking and powdering paint in the figurative scenes in the tablinum. Scientific analysis of samples from these wall paintings has allowed the partners to gain a fuller understanding of the original materials and techniques, and agents and mechanisms leading to their deterioration, to develop a methodological approach to their conservation.

Scientific study was also carried out on salts and biogrowth found in different areas of the room. Combining information from the environmental monitoring and laboratory research, scientists attempted to understand the mechanisms of deterioration, the correlation between salt activity, ground moisture, and microbiological growth, which is affecting the plasters and wall paintings in the tablinum. Comparisons were made with similar deterioration phenomena found on other sites in the Vesuvian region.