The scientific investigation for the study and conservation of the wooden model of S. Maria della Consolazione's church (Todi, Italy)

The focus of this work is the wood polychrome model of the church of S. Maria della Consolazione in Todi, an artefact whose author and historical events are not completely known except a general reference to the construction period of the church (1508–1607 AD). In this study, original and additional materials were examined in order to provide a deeper understanding of the painting and assembly techniques, and a greater awareness of how well preserved the object is, as well as an analysis of previous preservation and conservation interventions. The samples from the painted surfaces were examined by means of micro-Raman spectroscopy, fourier transform infrared (FTIR) spectrometry and internal microstratigraphic analysis. Thin sections of the wood samples were examined under an optical transmission light microscope in order to identify the botanical species. The results shown in this paper suggest the possibility that the original painted layers are made of calcium carbonate white, red ochre and indigo and they were applied by protein binder without any ground layer. Some non-original pigments were found on the model surface like Prussian blue and chrome yellow. Concerning wood components, poplar was characterized both in the original and non-original parts of the model whereas pine species were detected only in the restoration elements.