A research team has successfully detected the presence of ink in the Herculaneum Papyri, scrolls carbonized by the eruption of Vesuvius in 79 AD, using a surface topography technique. This breakthrough is crucial because the carbon-based ink in these manuscripts has a very similar composition to the carbonized papyrus itself, rendering it virtually invisible to conventional imaging methods like X-ray tomography. The new non-destructive methodology allows for the identification of inscriptions without unrolling or damaging the fragile documents.

The method relies on observing subtle variations in the surface topography of the papyrus. Carbon ink, when applied, creates a slightly raised layer or relief on the material. Although these differences are minimal, on the order of tens of micrometers, they are detectable with high-resolution optical scanners. The researchers employed a 3D scanning system that precisely measures the height of each point on the surface, thereby revealing writing patterns that previously remained hidden. This technique complements and overcomes the limitations of X-ray phase-contrast tomography, which has had limited success in detecting ink on these papyri.

This discovery opens a new avenue for reading the thousands of Herculaneum papyrus fragments that have yet to be deciphered. The ability to detect ink without unrolling the scrolls is fundamental, as many would disintegrate upon manipulation. Understanding the content of these texts could shed light on the philosophy, literature, and science of classical antiquity, offering a unique window into a Roman villa's library. The next step will be to apply this technique to a larger number of papyri and develop algorithms for automatic text reconstruction.