A Box Full of Research: Early Twentieth-Century Documentation on the Scientific Investigation and Restoration of the Eight Group Portraits by Frans Hals*

This paper outlines the historical and art historical context and significance of unique documentation concerning the restoration of the eight Hals group portraits at the Frans Hals Museum between 1911 and 1927. It explains the background and reasons for the research and its extensive documentation, as well as the importance of the material as the first interdisciplinary collaboration in the Netherlands between an art historian, restorers, and a chemist in relation to the cleaning of artworks. Besides written reports and photographs, the documentation includes a box of materials relating to scientific research, including samples of removed varnish and a set of colour photographs showing the cleaning process - the earliest such images in the history of conservation. During the recent conservation of Hals’s three Regent portraits, the study of this historical documentation enabled a deeper understanding of the condition of the paintings and their material history, while also shedding light on early twentieth-century Dutch conservation and art history.