About

The ThERA project reflects the commitment of the CdE-DTC Lazio to promoting innovative, open-access research in the field of cultural heritage. Through the integration of epigraphic expertise and advanced digital methodologies, ThERA contributes to the preservation, study, and public accessibility of a unique corpus of ancient graffiti. The project stands as a model of interdisciplinary collaboration and of the use of digital infrastructures to generate new knowledge while safeguarding particularly fragile archaeological evidence.

The ThERA project
Funding and team
Purposes of Rubbings Digitisation
Rubbings Digitisation: Technical Aspects
Archaeological site
Acknowledgements
Licence

The aim of the ThERA project is the open-access publication of a digital archive of inscription rubbings from the "Agora of the Gods" , located on a rocky outcrop on the island of Santorini (ancient Thera). For each rubbing, a high-resolution scan is produced, accompanied by an epigraphic record and its geolocation on a dynamic map.

The Agora of the Gods in Thera preserves a concentration of rock graffiti, many of which are votive or bear personal names. These inscriptions, carved on the natural rock surfaces surrounding the sacred area, offer insights into informal writing practices and the interaction of individuals within the sacred space. They are typically brief, often consisting of a single name, a divine epithet, or words with erotic connotations — all attesting to the spontaneous nature of the act of writing.

The graffiti display two main engraving techniques. The more common consists of a broad, shallow groove, made with a wide-tipped tool, widely used from the late 7th to early 6th century BCE. A second technique involves a narrow V‑shaped groove, about 2 mm wide, produced with a pointed tool. The layout of the inscriptions varies: some are placed irregularly on the rock surface, others align with natural edges, and several are enclosed within frames. A unique case is inscription no. 567 (IThera057), which includes three semicircles outside the frame.

ThERA is part of the Extended Partnership project titled "CHANGES" (CUP B83C22005060006 Project Code: PE000020, ‘Education and Research’- Component 2 ‘From Research to Enterprise) under Theme 5. "Humanities and Cultural Heritage as Laboratories of Innovation and Creativity," funded by the European Union – NextGenerationEU, as part of the activities assigned to the Associazione Centro di Eccellenza DTC. It is coordinated by Alessandra Inglese, Professor of Greek History and Epigraphy at the University of Rome ‘Tor Vergata’, and realised with the technical and scientific contribution of Valentina Mignosa, Marika Griffo, Simone Lucchetti, Luigi Tessarolo, and Virgilio Costa.

ThERA proposes, for the first time, the digitisation of rubbings through an interdisciplinary research, aimed at valorising these documents not only as reproductions of inscriptions, but also as cultural legacy to be preserved and valorised.

There are two main types of impressions most commonly used in the study of Greek epigraphy: the squeeze and the frottage (or rubbing) methods.

In the first case, a squeeze is created by pressing a damp sheet of special paper onto the surface of the inscription. The paper, once moistened, is pressed into the carved areas using soft tools or brushes to ensure that every detail of the text is captured. After drying, the paper hardens into a three-dimensional negative impression, faithfully reproducing the depth and texture of the inscription.

The second method, rubbing, involves placing a sheet of thin, flexible paper (sketch paper) firmly over the stone and using a soft, elastic and non-porous piece of cloth to spread graphite powder over the paper. The pigment adheres to the raised areas while leaving the recessed parts untouched, creating a two-dimensional image of the inscription. Both techniques are essential tools in the documentation and study of ancient inscriptions, especially when dealing with documents in situ and subject to erosion.

It should be noted that casting, especially when performed using squeezes, can harm the outermost layer of the document and, in cases involving very fragile stone, the substrate itself.

The quality of the rubbings varies according to the state of preservation of the documents. The rubbings can sometimes reveal traces on the stone that are not visible in the autopsy, as the graffiti in IThera028 (IG XII 3, 1313; see here): the engraved ship was invisible to the naked eye and its recognition was only possible thanks to the rubbing. The rubbings of the inscriptions from the Agora of the Gods are archived in the Laboratory of Greek Epigraphy at the Università di Roma Tor Vergata. The aim of their digitisation is not only their conservation for the future - both frottages and the rock inscriptions of the "Agora of the Gods" are continuously exposed to erosion and scouring - but also their open and easy access to scholars and the public.

Furthermore, to ensure full usability of the rubbing, we decided to add all the relevant information about the text and the rubbing itself in single epigraphic records in TEI EpiDoc. This includes technical details such as the type of carving, the size of the letters, and any graphic notations used.

In the context of the digitization of tangible cultural heritage objects, creating high-resolution digital copies of planar surfaces such as paintings, murals, engravings, manuscripts, and similar works enables the visualization of details that are difficult to discern with the naked eye.

In the case of frottage, the digital acquisition is two-dimensional because of the absence of a third dimension—or more precisely, the minimal thickness of the paper used for the process.

The technique used to digitize the rubbings is the multiple parallel axis gigapixel photography. This approach achieves great image quality (surpassing nodal photography due to its closer proximity to the subject) while avoiding the physical contact with the document that is necessary in scanning.

For more details check our article: Alessandra Inglese, Valentina Mignosa, Marika Griffo, Simone Lucchetti (2025). A Heritage of Paper and Stone: The ThERA project. Science and Technology for Cultural Heritage 1, vol. 33, pp. 63-77.

The ThERA project gratefully acknowledges the Greek Ministry of Culture and the Ephorate of Antiquities of the Cyclades for their support and for granting permission to publish the digital images of the inscriptions. Reproduction is authorized for this use only. All copyrights remain with the Greek Ministry of Culture.

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