the artifacts. In 2009, the Institut de France in conjunction with the French National Center for Scientific Research imaged two intact Herculaneum papyri using X-ray micro-computed tomography (micro-CT) to reveal the interior structures of the scrolls. The team heading the project estimated that if the scrolls were fully unwound it would be between long. The internal structure of the rolls was revealed to be extremely compact and convoluted, defeating the automatic unwrapping computer algorithms that the team had developed. Manual examination of small segments of the internal structure of the rolls proved more successful, unveiling the individual fibres of the papyrus. Unfortunately, no ink could be seen on the small samples imaged, because carbon-based inks are not visible on the carbonized scrolls. However, some scrolls were written with ink containing lead. Virtual unrolling According to Bukreeva et al. 2016, "The procedure of virtual unrolling can be divided into three main steps: volumetric scanning, segmentation, layered texture generation and restoration." Seales et al. 2005 and 2013 developed promising software that integrates functions of flattening and unrolling based on mass-spring surface simulations. Samko et al. 2014 proposed algorithms to solve problems of touching points between adjacent sheet layers. In 2015, a team led by Dr. Vito Mocella, from the National Research Council's Institute for Microelectronics and Microsystems (CNR-IMM), has announced that "... X-ray phase-contrast tomography (XPCT) can reveal various letters hidden inside the precious papyri without unrolling them. [...] This pioneering research opens up new prospects not only for the many papyri still unopened, but also for others that have not yet been discovered, perhaps including a second library of Latin papyri at a lower, as yet unexcavated level of the Villa." The microscopic relief of letters – a tenth of a millimeter – on the papyri seems to be enough to create a noticeable phase contrast with the XPCT scans. This team was even able to identify some writing on a still-rolled scroll. With the aim of making these scans cogent, a team is working with the National Science Foundation and Google to develop software which can sort through these displaced letters and figure out where they are located on the scroll. Following the pioneering results of Dr. Mocella et al., in 2016 another team led by Dr. G. Ranocchia and Dr. A. Cedola announced encouraging results by means of the non-destructive Synchrotron X-ray phase-contrast tomography (XPCT) technique. In September 2016,