Abigail Mack, Angela Chang and Shelley Sturman
In response to the challenges of preserving the surfaces of its painted outdoor sculptures, the Object Conservation Department at the National Gallery of Art has undertaken research to compare commercial paint systems for physical and chemical durability. Specifically, black matte finishes are being studied, as they have shown to be the most fragile and difficult to maintain. The need to repaint, as a last resort, has prompted an exploration into alternative, commercial paints. This paper will report on studies carried out on the condition of matte black painted outdoor sculptures at the NGA and describe ongoing, comparative testing.
While the need to repaint outdoor sculpture represents an exception to a conservator’s usual responsibility to preserve an original surface, s/he may still be reluctant to repaint due to costs and complex applications of modern paint systems on a large scale. Selecting an appropriate paint system presents an additional ethical challenge: a conservator’s obligation to respect an artist’s paint choice may conflict with the practicality of preserving an acceptable appearance. For example, fragile paint surfaces may not withstand the maintenance necessary in an outdoor environment. As dialogue with artists or artists’ estates fosters understanding of their view of materials and aesthetics, conservators knowledgeable about modern paint systems may offer suggestions for durable materials compatible with the artists’ aesthetic choices.
The first part of this paper evaluates the current condition of five painted outdoor sculptures at the National Gallery of Art. Their various exposures to the same environment in real time, up to ten years, have allowed for a prudent evaluation of their performance.
The second part of this paper investigates commercial matte paint systems for repainting outdoor sculpture. Nine types of commercial paints were chosen in consultation with their manufacturers and include those currently used on NGA sculptures. After real-time and accelerated aging, routine testing and analysis of physical and chemical attributes will be used to monitor and compare deterioration of these paints.