BINDING MEDIA IDENTIFICATION IN PAINTED ETHNOGRAPHIC OBJECTS
DUSAN STULIK, & HENRY FLORSHEIM
Working with the proposed procedure is easy, and analytical methods for the individual tests or the whole identification system can be learned in a very short time. The procedure was originally developed for participants in “The Consolidation of Painted Ethnographic Objects,” a training course, held at the Getty Conservation Institute in June 1990. About 20 practicing conservators of ethnographic art worked with the system for 2 days. Regardless of their previous laboratory experience, all participants mastered identification procedures and were able to identify binding media types in test samples, painted facsimiles, and selected authentic ethnographic objects. The major advantage of the procedure is the fact that the majority of reagents, tools, and lab ware is readily available from laboratory supply houses (table 2); a kit can be assembled quickly and easily.
A systematic instrumental approach to the identification of binding media has been published recently (Erhardt et al. 1988). The approach outlined requires the availability of infrared, gas chromatographic, and high-pressure liquid chromatographic instrumentation. While these instruments are frequently not available to a museum conservator, they do provide advantages such as ease of documentation and a somewhat smaller sample requirement. They may also provide information that is not available by our less sophisticated procedure, such as the possible identification of specific proteins, gums, or oils.
Like any analytical method, our procedure is not universally applicable. Certain pigments interfere with some of the tests. Insufficient sample may be available to satisfy the requirements for some or all of the tests, or the analyst may require information concerning the presence of specific binders or drying oils. In such instances the reader is referred to the literature (Erhardt et al. 1988; Masschelein-Kleiner 1986; Mills and White 1987).
Our tests were designed to provide quick answers to binding media questions at low cost to a conservation laboratory. As such, they cannot provide answers to all binding media questions or solve complex binding media “puzzles.” They can play a screening role in these complex cases, and the test results can be used to guide further investigation. In such cases, it is necessary to apply advanced instrumental techniques, and there are instances when even the most sophisticated analytical methods cannot give straightforward answers.
Work is in progress to improve the analytical performance of the procedures, and we are constantly searching for new technologies that might improve detection limits for binding media tests, improve the selectivity of the tests, or simplify the analytical procedure.
IMPORTANT NOTE: When working with the binding media tests, it is necessary to become acquainted with material safety data sheets for all reagents and practice safe and responsible laboratory procedures.
We express our thanks to Frank Preusser, Neville Agnew, and Marta de la Torre of the Getty Conservation Institute for their support of the project; to Sue Walston of the Australian National Museum for numerous discussions and friendly advice; and to our colleagues Cecily Druzik and Karen Cole for their computer graphics work on text figures.