Overview
- The PLOS ONE paper published on Wednesday, Sept. 16, 2026 reports experiments showing that small amounts of lead in ink produce a much stronger, element‑specific X‑ray signal than carbon ink on carbonized papyrus.
- Researchers had students write known texts on modern papyrus with inks of varied lead content, carbonized the rolls, and then used X‑ray CT and adapted virtual‑unrolling software to recover readable passages from the replicas.
- In scans of the model scrolls leaded ink absorbed as much as 25 times more X‑rays than the surrounding papyrus and lead at concentrations near 25 micrograms per square centimeter was detectable by both CT and X‑ray fluorescence.
- The team demonstrated that inexpensive handheld X‑ray fluorescence (XRF) instruments could be used as a non‑destructive pre‑screen to flag Herculaneum scrolls likely to yield legible text before committing to full CT imaging and computational unwrapping.
- Limits remain: not all ancient inks contain lead, environmental contamination or other elements can confuse signals, and no systematic lead‑screening of the historic Herculaneum collection has yet been carried out so conservators must approve any field program.