Richard C. Wolbers and Margaret A. Little
In approaching surface cleaning of an art object, treatment typically starts with analysis of the object to understand the materials used to create it, and the nature of the soiling on the surface. This information aids in designing the cleaning system used in the treatment. In situations where the nature of the soiling and/or the geography of the object’s surface are complex, it can also be important to find a way to monitor and measure the efficacy and level of cleaning of the surface.
An approach to designing a cleaning system and measuring the level of cleaning will be discussed in the context of the cleaning of two painted plaster busts in the collection of the Winterthur Library Archives. The busts, one of Pierre Samuel du Pont de Nemours, the other of his first wife Nicole Charlotte Marie Louise Le Dée de Rencourt, are copies of plaster busts attributed to Louis Simon Boizot which date to 1775-6. These objects were chosen for inclusion in a Winterthur Museum exhibition, and required treatment prior to exhibit, specifically cleaning, minor paint consolidation and loss compensation. The painted surfaces of the busts were heavily soiled, and removing these soils efficiently and evenly presented an interesting challenge, given the range of surface materials (including a possible original painted surface), overpaint and exposed plaster surfaces.