STATE OF CONSERVATION
Among the examination methods used in ascertaining the state of preservation and verifying the existence and extent of non-original parts of the painted surface are raking light photography (RAD) and visible fluorescence induced by ultraviolet radiation (UVF).
Observation in raking light made it easy the mapping of areas of bulging and depression of the plaster, detached from the masonry due to significant stormwater infiltrations. Widespread fractures and cracks of varying extent have been identified across the entire surface, as well as groutings attributable to previous restoration work.
UV light imaging has highlighted the presence of a film that markedly dulls the background. The petroleum green fluorescence may be due to the uneven application of an acrylic resin-based fixative whose composition was later confirmed by microchemical analysis. It is hypothesized to be Paraloid, as documented in records related to restorations in the 1990s.
