Deciphering 4000-year-old cuneiform letters hidden in clay envelopes using a mobile X-ray computed tomography scanner

Abstract Hundreds of cuneiform clay tablets unearthed in South-western Asia remain sealed within clay envelopes, leaving their texts inaccessible to Assyriologists. Computed tomography (CT) enables looking inside the clay envelopes non-destructively. An interdisciplinary team developed a transportable high-definition CT scanner named by ENCI, designed for on-site use in museums and archives. ENCI allows researchers to visualise the cuneiform text written on hidden tablets, study clay inclusions, and analyse manufacturing techniques without opening the tablets. First deployed at the Louvre Museum in Paris in 2024, it was later used at the Museum of Anatolian Civilisations in Ankara to scan around fifty encased tablets, many of them letters. Combined with advanced 3D surface extraction and visualisation software, ENCI enables virtual unwrapping and detailed exploration of small objects. This technology opens new possibilities for studying cultural heritage artefacts on site, while also revealing mineral and organic inclusions and evidence of envelope formation methods.