A Research Survey into Stucco Decorations and Clay Statues (Part 8)
Since 2021, The Japan Center for International Cooperation in Conservation has been involved in a research survey on stucco decoration and clay statues under the research project “Technology for the Conservation and Restoration of Cultural Heritage” program.
From November 8 to 12, 2025, we visited Florence to conduct research and present our findings on the clay statue groups created by late Renaissance and Mannerist sculptors Pietro Francavilla and Antonio di Annibale Marchissi. These sculptures were originally produced as elements of a temporary façade erected at the Santa Maria del Fiore Cathedral in 1589 to celebrate the wedding of Grand Duke Ferdinando I de’ Medici of Tuscany and Christine of Lorraine. After the temporary structure was dismantled, the works were placed for a time along the nave walls inside the cathedral. In the nineteenth century, they were moved to the attic space on the northeastern side of the cathedral dome, where they remain today under the care of the Opera di Santa Maria del Fiore.
In the recent results briefing, we shared within our research team the findings obtained through the non-destructive investigations conducted to date— including photographic documentation using visible, infrared, and ultraviolet light, X-radiography, fiberscope exploration, and 3D measurements. These investigations enabled us to identify key structural features, such as the multi-layered composition centered on clay and the design based on the modularization of individual components. We also confirmed traces of surface finishes and gilding, providing important clues to the original production processes of the works. Going forward, we plan to gradually shift toward micro-destructive analyses involving limited sampling—conducted under appropriate ethical standards and with full consideration for conservation science— to obtain detailed information that cannot be adequately captured through non-destructive methods alone. Through this approach, we aim to clarify the correlation between the works’ structural characteristics and their deterioration mechanisms, and ultimately contribute to the development of appropriate conservation and restoration strategies.
Furthermore, this study aims to clarify both the universality of stucco decoration and clay statue traditions—elements that have been transmitted across regions and historical periods—and the diversity of their technical developments. As an interdisciplinary endeavor that spans art history, conservation studies, materials science, and cultural heritage studies, the project depends fundamentally on the international exchange of knowledge and collaborative research. Moving forward, we intend to strengthen our partnerships with specialists around the world and deepen interdisciplinary dialogue, thereby advancing our work in a steady and informed manner as we strive to open new frameworks for understanding within the field of cultural heritage research.