An Innovative, Multidisciplinary Approach to the Restoration of Paintings in a Hypogeal Environment: the Case of the Etruscan Tomba degli Scudi (4th century B.C.) in Tarquinia

The Tomba degli Scudi, an important Etruscan hypogeum from the 4th-century BC, is situated in the Monterozzi necropolis of Tarquinia, Italy, and it is acknowledged as a UNESCO heritage site since 2004. The restoration of its mural paintings epitomizes an exemplary interdisciplinary collaboration, encompassing restorers, archaeologists, and scientists. As we embarked upon the restoration, collaborative discussions precipitated significant revelations in conservation, archaeology, and biology. This collaboration elucidated the conservation history, the unique execution technique, and thorough examinations of environmental parameters. The inaugural phase of this initiative was generously financed by Fondo per l’Ambiente Italiano, the Italian Environment Fund, and the Soprintendenza Archeologia, Belle Arti e Paesaggio per l’Area metropolitana di Roma, la provincia di Viterbo e l’Etruria meridionale, focusing on the atrium murals. Subsequently, murals in the sepulchral chamber were rehabilitated. Given the distinct nature of the hypogeal environment, the methodologies and material selection demand meticulous consideration, ensuring alignment with pre-Roman mural traditions in the Italic region. Simultaneously, an exhaustive historiographic assessment furnished comprehensive insights into the conservation history of the hypogeum. Rigorous analysis and restoration accuracy led to a groundbreaking revelation—depictions of human entities used modular templates for individual body components, most potentially crafted from sturdy materials. These templates, which manifested in four scales, corresponded to the hierarchical status of the depicted characters. Historically, the employment of such modular templates, termed patroni and antibola, was recognized exclusively from the early Middle Ages onward in the western and eastern art traditions, because no prior evidence of this painting modality existed. Consequently, this discovery infers that the inception of this technique predates prior assumptions by approximately a millennium, thereby refining our understanding of technological transitions from Classical Antiquity to the Middle Ages. An important and innovative aspect of this project resides in the exhaustive microbiological examination. Although the Tarquin hypogea had been intermittently probed during preceding restoration efforts, the bacterial and fungal communities, which sustain a nuanced and fragile equilibrium within these environments, had not been rigorously and holistically studied. In this endeavor, a microbiological assessment was executed before, during, and post the restoration stages. The outcomes were compared against data from other hypogea, transforming the Necropolis tombs into genuine scientific research hubs. Notably, the biological examination of the white biological deposit in the paintings was identified as moonmilk, which is an exceptional microbial-derived calcite that conserved the murals instead of impairing them. However, several preservation challenges emerged, especially regarding post-restoration disinfestation practices. Thus, a targeted study of bacterial communities yielded novel insights, heralding a new conservation approach. Concurrently, a pioneering method integrating ultraviolet fluorescence with 3D techniques was deployed. An essential dimension of the project was investigating the interplay between the preparatory strata of the paintings and the pictorial film. This discourse precipitated intriguing procedural decisions, proffering a foundation for subsequent deliberations on pictorial integration in archaeological settings.