A review of solvent action on oil paint

The science of oil paint cleaning is an interdisciplinary and challenging field of study due to the complex nature of both paintings and cleaning materials. The topic requires an intimate and iterative collaboration between conservation scientists and paintings conservators. In such an interdisciplinary field, it can sometimes be difficult to interpret the practical applicability of the available literature. This review aims to bring both conservators and scientist up-to-date on the recent advances in the literature on oil paint cleaning and proposes a framework for experimental and theoretical investigations into solvent transport in oil paint. We define the physicochemical processes that occur simultaneously during cleaning as solvent action and investigate how these processes vary with the polymeric structure of the oil binding medium. The sections in this overview of the technical cleaning literature are divided into solubility, swelling and diffusion, leaching, solvent evaporation and retention and solvent-mediated chemical reactions. Models that have been used to predict varnish solubility or oil paint swelling, such as Teas chart, are critically reviewed from the perspective of the most recent developments in the various scientific disciplines involved. Technological developments in the field of modern materials for solvent- and water-based cleaning are also discussed. Finally, an outlook for the field of cleaning science is presented.