ArtGarden is a network-project funded by the Belgian Federal Public Planning Service Science Policy (Belspo, 2016-2020). It is part of the BRAIN-be research-program (Belgian Research Action through Interdisciplinary Networks). The project focuses on the conservation treatment of seven Enclosed Gardens and on the complex issues of long-term preservation of historic mix-media objects. Scientific partners of ArtGarden KU Leuven (Illuminare - Book Heritage Lab, ESAT & Digital Lab - University Libraries), the Chemistry Department (AXES and Heritage Science) of the University of Antwerp, and the Laboratories and the Preventive Conservation Unit of the Royal Institute for Cultural Heritage (KIK-IRPA, coordinator). The presented research is part of the art technical and imaging study of the Enclosed Gardens by the team of KU Leuven (2017-2018).Papers presented at the twentieth symposium for the study of underdrawing and technology in painting held in Mechelen and Leuven, 11-13 january 2017