Kell Mortensen and Poul Erik Lindelof from the Niels Bohr Institute are part of this interdisciplinary research team. Together with researchers from other departments at the University of Copenhagen and the ESRF in Grenoble, they have analyzed papyrus fragments with X-ray microscopy. They have found that the ink on the fragments contains novel lead compounds, which indicate that the lead has been used as a desiccant, and not as a dye as previously thought. A similar drying technique was used by painters in the 15th century.