Ink matters: imaging and analysing ink writing on carbonised Roman wax tablets at the MANN with Olivier Bonnerot and Samaneh Ehteram

In April 2026, the National Archaeological Museum of Naples hosted a research mission by Dr Olivier Bonnerot and Samaneh Ehteram, devoted to some of the most fragile and fascinating written objects from the Roman world: the carbonised wax tablets from Pompeii and Herculaneum. Framed as a collaboration between the TabulaRasa project and the University of Hamburg’s Centre for the Study of Manuscript Cultures, the mission focused on a deceptively simple question: can modern imaging and analysis help us read ink traces that are almost invisible to the naked eye, and tell us what kind of ink was used?

The objects at the centre of the mission are exceptional witnesses to everyday writing practices in Roman Campania. Wax tablets were used for documents, contracts, legal records, accounts, and correspondence. Especially when used for legal documents, wax codices combined incised writing — a sgraffio, on waxed recesses — with ink writing — atramentum, on dedicated portions of the wooden surfaces. The latter was the focus of Olivier and Samaneh’s mission: impossible. In ordinary conditions, the dark line of ink would stand out clearly from the lighter background of the tablet. But the tablets from Pompeii and Herculaneum underwent a very different history. Buried and carbonised by the eruption of Vesuvius, their wooden surfaces turned black. Ink, especially if carbon-based, also appears dark. The result is a near-total loss of contrast: black writing on black wood.

What may look like a piece of charcoal for a barbecue is actually the 2,000-year-old middle tablet of a wax triptych from the archive of the Pompeian banker Caecilius Jucundus, with a substantial amount of ink writing still to be deciphered by an expert eye: CIL IV 3340, II tab. 2, verso (p. 4), from the archive of Caecilius Jucundus, MANN. Photo by M. Stefanile, using a Sony a7IV; su concessione del Ministero della Cultura – Museo Archeologico Nazionale di Napoli; line drawing by Karl Zangemeister, in CIL IV 3340, p. 282.

This is precisely where our mission comes into play. While techniques such as Reflectance Transformation Imaging are highly effective for reading incised or scratched marks, ink presents a different problem. If the eye cannot distinguish the stroke from the surface, perhaps wavelengths beyond ordinary vision can. The mission therefore combined hyperspectral imaging with non-destructive elemental analysis by X-ray fluorescence spectroscopy (X-ray… what? You can learn about that in the excellent CSMC Guide to Written Artefact Profiling online 😊). Together, these approaches were designed not only to improve the legibility of the texts, but also to investigate what the inks themselves were made of.

The work took place from 20 to 24 April 2026 in the MANN’s Restoration Laboratory, a setting generously made available by the Museum to ensure ideal conservation and working conditions. The museum side of the collaboration involved Director Francesco Sirano, Floriana Miele, Mariateresa Operetto, and Valentina Fiorito, while the TabulaRasa supporting team included Michele Cammarosano, Giuseppe Camodeca, Luca De Curtis, and Michele Stefanile.

Top row, from left: Samaneh Ehteram and Olivier Bonnerot (CSMC), Mariateresa Operetto (Head of Conservation at MANN), and Floriana Miele (Curator of Coin Cabinet at MANN). Bottom row: …the tablets! (Photo: M. Cammarosano; su concessione del Ministero della Cultura – Museo Archeologico Nazionale di Napoli)

A sample of 28 tablets from both Herculaneum and Pompeii had previously been singled out by Giuseppe Camodeca, one of the leading specialists in the decipherment and interpretation of this type of document, and the foremost expert on the Roman epigraphic corpora from the Vesuvian area. The selection was made primarily on the basis of the presence of ink writing that is particularly challenging to read.

Olivier Bonnerot and Samaneh Ehteram had at their disposal a true gem of multispectral technology: a brand-new Muses9-HS3-7 system by Spectricon, a leading company in the field, in a dedicated configuration applied here for the first time to archaeometric research. For this reason, on the first day we were joined directly from Crete by electronic and computer engineer Athanasios Tsapras of Spectricon, to ensure optimal calibration of the instrument. Wow!

The Hamburg–Neapolitan team also had the honour of a visit from the Museum’s Director, Francesco Sirano, and, by a fortunate coincidence, the mission was also featured in the report that the newspaper Il Mattino devoted to the MANN on April 21 (here on YouTube).

The efforts bore fruit. At a preliminary assessment, the multispectral images appear to be of excellent quality, with the ink traces becoming almost magically visible. This is already demonstrated by the case of a tablet fragment from Herculaneum containing a fascinating allusion to the olive harvest, which Professor Camodeca is preparing to publish in the journal Codex (no spoiler… we will be sure to tell about that in a future post!). The new multispectral image was able to confirm Camodeca’s tentative reading, and it is reasonable to hope that, once post-processing has been completed, other photographed tablets too will yield good results.

Hyperspectral imaging of carbonised wax tablets (photos: M. Cammarosano), and result image for TH A41, from Herculaneum (photo: O. Bonnerot, taken in the SWIR at 1600 nm, flattened); su concessione del Ministero della Cultura – Museo Archeologico Nazionale di Napoli. TH A41 will be published soon by Giuseppe Camodeca in the forthcoming paper “Vendita di olive sulla pianta in una inedita tabula herculanensis (TH2 A41): il primo riscontro nei documenti della prassi giuridica”, to appear in Codex 7.

XRF analysis of the inks proved more challenging, due to the extreme difficulty of identifying the traces of writing on the instrument’s screen and therefore of focusing the beam exactly on the desired point. Besides highlighting the specific methodological difficulties involved in the study of these particular written artefacts, this part of the mission nevertheless brought to light significant data, which will also be presented to the scholarly community in a future publication.

Finally, the mission also had a welcome public dimension. On Monday, 20 April 2026, Olivier gave a lecture at the University of Naples ‘L’Orientale’ entitled “The CSMC Mobile Lab and the non-destructive analysis of written artefacts: insights into inks and pigments on ancient papyri”, which we had announced in a previous post and was also streamed online.

With this mission, a further step has been taken in the testing of the different documentation and analytical methods that can be applied to these fragile written artefacts, whose nature is both complex and multifaceted. TabulaRasa’s aim is for this process to lead to the development of an effective protocol for the documentation and interpretation not only of the Roman wax tablets from the Vesuvian area, but of the wax-tablet medium in all its historical forms.

We can only warmly thank Olivier and Samaneh, together with the entire CSMC in Hamburg, for the opportunity of such a productive and exciting partnership, and the Director and staff of the National Archaeological Museum of Naples for the dedication, expertise, and generosity with which they constantly support our research, as well as that of all those who care about these wonderful predecessors of our tablets!

Olivier and Samaneh at the MANN main entrance, and while working at XRF analysis. (Photos: M. Cammarosano; su concessione del Ministero della Cultura – Museo Archeologico Nazionale di Napoli)

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