Emma Richardson, Rachel Rivenc, and Tom Learner
Abstract
In recent years there has been growing interest in synthetic materials within the museum environment; both from an identification point of view and in order to determine their condition. Since their development in the late 19th Century, synthetic polymers have moved steadily into almost every area of life, and as a consequence, into a growing number of museum collections. Many classes of plastic have become household names: polyethylene, polyester, polyurethane, acrylic, polyvinyl chloride (PVC), and cellulose acetate, to name just a few. They are typically cheap, lightweight, and readily molded and shaped into all kinds of forms and structures. Since their introduction, they have opened up incredible new design possibilities for sculptors, architects, and designers.
Whilst the general perception of plastics is one of persistence, i.e. materials that do not readily biodegrade, many are already exhibiting serious signs of deterioration, often appearing with little or no warning. Common signs include discoloration, crazing and cracking, warping, becoming sticky due to plasticizer migration, and in extreme cases turning completely to powder.
The degradation and stabilization of organic polymers vary through the classes, therefore illustrating the need for positive identification within collections, which is not always easy with limited sampling of artifacts. This is particularly true where the surface and finish of an artwork is inherent to its artistic intent, such as the pieces synonymous with the postwar Los Angeles art scene. Taking inspiration from the Californian landscape, many of these artists were adopting highly innovative fabrication processes to create seamless, bright, and pristine-looking objects. The sculptors, in particular, became well known for utilizing a vast array of new resins, paints, and plastics, all of which were being developed at that time for use in the aerospace, boat, automobile, and even surfboard industries.
The Getty Conservation Institute is undertaking a major study into the novel and often experimental technologies applied by many of the most prominent of these artists, such as Peter Alexander, Robert Irwin, Craig Kauffman, John McCracken, Helen Pashgian and De Wain Valentine; their pristine surfaces often earning them the label ‘Finish Fetish’. An important part of this project has been the use of a portable ATR instrument – with a curved ATR measuring head – for rapid, non-invasive, in situ analysis of the materials used in these artworks. Although contact with the object is required with this instrumental set up, the force exerted during measurement is minimal and in most cases extremely high quality FTIR spectra were obtained without leaving any mark on these typically delicate surfaces.