Scholars have traditionally focused on the subjects and meanings of Hieronymus Bosch's works, whereas issues of painting technique, workshop participation, and condition of extant pictures have received considerably less attention. Since 2010, the Bosch Research and Conservation Project has been studying these works using modern methods. The team has documented Bosch's extant paintings with infrared reflectography and ultra high-resolution digital macro photography, both in infrared and visible light. Together with microscopic study of the paintings, this has enabled the team to write extensive and critical research reports describing the techniques and condition of the works, published in this extraordinary volume for the first time. Distributed for Mercatorfonds Based on six years of study done by the Bosch Research and Conservation Project, this book represents the most comprehensive study ever done of the materiality of Hieronymus Bosch's paintings. 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.