Medieval inscriptions in Lazio: a new digital documentation protocol reveals the secrets of the engravings and their production cycle through the gestures of the artisan
An experimental archaeology study conducted by the Department of Ancient World Studies at Sapienza University takes a profoundly innovative approach to the study of medieval inscriptions on stone. The research, published in PLOS ONE, introduces accessible and replicable digital protocols with the aim of reconstructing the actions carried out by artisans in stoneworking and recognising the techniques used and the level of skill involved.
"We selected two case studies referring to different periods and asked an expert artisan to create a collection of epigraphic replicas that served as a basis for comparison in interpreting the traces observed on the two important medieval epigraphs from northern Lazio”, says Giulia Previti, a researcher at the Department of Ancient World Studies. “The first is the monumental inscription of Pope Leo IV (9th century), created for the foundation of the city of Leopoli-Cencelle, a site that has been excavated by Sapienza University since 1994. the second is a 13th-century funerary slab preserved at the Museo Civico of Viterbo and dedicated to Pietro di Vico, a prominent figure in local politics”.
In this context, experimental archaeology and traceology play a key role because, by integrating qualitative and quantitative methods, they allow us to identify gestures, strategies and habits, types of tools used and operational sequences. In the study, a fundamental methodological contribution is represented by the use of micro-photogrammetry using a portable digital microscope: a non-invasive and non-destructive technique which, through the generation of a 3D model, enabled high-resolution and detailed documentation of immovable epigraphic surfaces. This research was conducted as part of the activities of the Laboratorio di Analisi Tecnologica e Funzionale dei Manufatti Preistorici (LTFAPA) of the Department of Ancient World Studies, which specialises in the analysis of archaeological artefacts made of stone, ceramic, bone and metal using microscopy techniques.
“This approach allows for a detailed analysis of the carved surfaces”, explains Cristina Lemorini, professor of Experimental Archaeology at Sapienza University and head of the LTFAPA Laboratory, "making it possible to collect data such as the direction, depth and inclination of the engravings, as well as the surface roughness and, above all, any overlaps of gestures and subsequent interventions, such as those of aesthetic restoration in vogue in the early 9th century. With this method, each engraved letter becomes tangible evidence of technical knowledge materialised in stone”.
The study carried out a systematic analysis of specific letters in the epigraphs, starting with the techniques used to create them, the stages of production (roughing, chiselling, finishing) and the tools identified (flat chisel, round-tipped chisel, percussion hammers ), also assessing the effect of deposition and post-depositional alteration processes on the legibility of the engraved surfaces and the extent to which these transformations have affected the visibility and preservation of technological traces.
The data collected not only provides technical information, but also allows us to understand the historical and cultural context in which the inscriptions were produced, offering a deeper insight into medieval societies through the material traces left behind by their written expressions.
The potential of this type of analysis is particularly evident in the field of epigraphy, where the topic of material production has long been neglected by scholars, thus introducing a highly innovative element into research.
References
Previti G, Kusumastuti S, Luci B, Malatesta L, Lemorini C, From chisel to inscription: affordable protocols for the digital documentation of stone carving techniques. An experimental archaeology and traceological approach applied to epigraphy. (2025) PLOS ONE 20(7): e0327303. https://doi.org/10.1371/journal.pone.0327303
Further Information
Giulia Previti
Department of Ancient World Studies
Cristina Lemorini
Department of Ancient World Studies