Luuk Hoogstede is a paintings conservator at SRAL, Maastricht. Ron Spronk is professor in art history at Queen’s University, Kingston, Ontario, Canada, and Radboud University, Nijmegen, the Netherlands. Matthijs Ilsink is the project coordinator of the Bosch Research and Conservation Project and teaches art history at Radboud University, Nijmegen, the Netherlands. Jos Koldeweij is professor in art history of the Middle Ages at Radboud University, Nijmegen, the Netherlands.