Rilievo digitale multi-scala e integrazione dei dati VIS e IR per la conservazione preventiva delle pitture murali. Il caso di studio del chiostro Verde nella basilica di Santa Maria Novella a Firenze.

The conservation of Cultural Heritage and its appropriate valorization require in-depth documentation in terms of both art history and the physical characteristics of position, shape, color, and geometry. The disciplines of surveying have refined digital data acquisition techniques, enabling the detection and representation of three-dimensional objects such as sculptures and archaeological finds, as well as large-scale elements like architectural structures, down to sub-millimeter scale elements with remarkable accuracy. From these backgrounds, digital survey technologies and their many potentials constitute indispensable methodologies for the preventive conservation of Cultural Heritage. Based on these requirements, the study moved towards researching and experimenting with methods able to meet the criteria for the planned conservation of detached wall paintings applied to various types of movable supports. The technique of detaching wall paintings ("strappo" and "stacco" techniques) from their natural support, used nowadays only in cases of extreme structural deterioration, has historically been one of the primary methods to prevent the loss of paintings subjected to various deterioration processes and to uncover the preparatory drawing of the fresco (sinopia). This is the context for the study of the fresco cycle in the Verde cloister in the basilica of Santa Maria Novella (Florence), which contains a large number of detached wall paintings, including works by Paolo Uccello, Dello Delli, and other minor painters. The detachment of the wall paintings from the cloister walls began with Domenico Fiscali and continued in 1952 with the Central Institute for Restoration in Rome. The work concluded with the transport, carried out in 1954 by Leonetto Tintori, onto various types of supports. Today, these frescoes show various types of degradation, including localized deformations, loss of functionality of the anchoring system to the masonry, rising dampness phenomena, and loss of original color. Starting from these problems, an interdisciplinary study was carried out on the frescoes and the architectural complex in which they are located, using Non-Invasive and Non-Destructive Techniques (NDTs), including infrared thermography (IRT), 3D laser scanning survey, Structure from Motion photogrammetry, topographic survey, and close-range laser scanning. These multi scale and multi-sensor digital methodologies are essential to built a critical apparatus of the state of conservation of the frescoes and to develop an appropriate conservation protocol. Through these surveys, it was possible to quantify the deformations suffered by the supports, acquire geometric control lines for monitoring the seasonal movements and deformations of the panels, and verify whether these movements have caused or will cause the formation of craquelures, cracks, or raising on the painted film. The interoperability of the multi analytical approach proposed in this doctoral thesis will enable periodic control of the flatness of the supports to assess the risks, monitor them, and analyze the causes and effects they have produced on the wall paintings. The final objective is to define an adequate conservation protocol suitable for this type of cultural object, but also potentially applicable to other case studies with similar problems. Indeed, it was observed that the conservation problems encountered at the Verde cloister are similar to those in other contexts (in the historical center of Florence there are many cloisters with detached wall paintings on Masonite, fiberglass, and composite supports that present serious degradation issues deriving from the supports).