Cleaning of Easel Paintings

Cleaning of easel paintings is traditionally carried out using organic solvents or aqueous solutions. One of the main limitations is due to the lack of control in the cleaning action when non-confined solvents and solutions are used. Undesired effects include swelling or solubilization of original artistic materials, uncontrolled or excessive removal of layers and patinas, and re-transport of solubilized matter through the porous matrix of the artifact. These issues can be effectively addressed by confinement of the cleaning fluids in gel networks. As a matter of fact, conservators have adopted several gel and ‘gel-like’ formulations (e.g. viscous dispersions of thickening agents), aiming at the non-invasive and gradual cleaning of works of art. This chapter reports on the main traditional systems and on the innovative gels and dispersions developed in the last decade in the framework of colloid and surface science for the preservation of cultural heritage. In particular, both highly retentive chemical gels and “peelable” viscoelastic dispersions are discussed, illustrating applicative procedures.