Jürg Meyer zur Capellen was born in Göttingen (Germany) in 1941. He taught art history at the universities of Freiburg, Cologne, and Münster. He has written widely on Renaissance painting and is directing the Raffael Projekt for more than 20 years.Claudio Falcucci was born in Colleferro (Italy) in 1967. He made his BSc in Nuclear Engeneering at the University La Sapienza in Rome in 1991 and concentrated on non-destructive testing techniques from X-ray to IR. He has published on Renaissance and Baroque painting and teaches at the La Sapienza since 1996.