Author's note
This research into marks and brands on panel paintings began in 1983, during the study of the 95 panel paintings mounted in the wainscotting between 1615 and 1620 in the Danish king Christian IV’s private chambers—the Winter Room, at Rosenborg Castle in Copenhagen. A grant from the Vlaamse Gemeenschap enabled research at the KIK-IRPA in 1986, which continued part-time from 1990 during the early years of my tenure at the Mauritshuis in The Hague. A grant from the Novo Nordisk Foundation, Denmark, awarded in 2000 further stimulated this research. To complement the study and provide a research infrastructure for the validation of panel makers' marks and brands, the Dendro4Art online portal was developed under my direction at CATS, SMK (Copenhagen), and the RKD (The Hague). The initiative was made possible through a generous grant from the Carlsberg Foundation, Denmark. Since 2010, the RKD has engaged in and coordinated the task of making my extensive archive of marks and brands on paintings accessible through its digital infrastructure. Further support—including grants from the Samuel H. Kress Foundation and the Mondriaan Fund to the RKD, as well as a personal grant from the Getty Conservation Institute, which enabled me to serve as a Scholar in Residence at their premises in Los Angeles—was instrumental in researching, reviewing and preparing the material presented here. Since 2023 I have been an Associate Researcher at the RKD, and I am deeply grateful for the support received from many institutions and numerous colleagues who—knowingly or not—have contributed valuable information to this archive over the past forty years. Angela Jager, with whom I have had many pleasurable and fruitful research collaborations, has been my anchor at the RKD and I highly value her engagement and editing of this document for the Marks on Art project.
Jørgen Wadum
Wadum Art Technological Studies
Associate Researcher
RKD – Netherlands Institute for Art History
Vanløse, June 2026