"The field of conservation has grown tremendously over the past 50 years and professional conservators must abide by a standard code of ethics. What was considered acceptable treatment for an object 50 years ago may no longer be appropriate. "-Sharon Koehler, Conservator
Modern conservation of art objects encompasses four
essential processes: 1) Examination to determine the extent of
deterioration, alteration, and loss; 2) Scientific analysis to
reveal structure and materials; 3) Preservation to retard or
prevent deterioration; and 4) Restoration to return the object
to its original appearance with minimal sacrifice of historic and
aesthetic integrity.
"Restoration" prior to World War II often meant covering up cracks and other damage and using artistic license to paint in missing decoration. The cosmetic appearance and market value of the "restored" object took precedence over historic integrity or long-term preservation. The early history of the Nasca drum at the Krannert Art Museum is a perfect example of these practices.
The alterations to the drum were partially revealed by X-rays, which showed structural cracks, patches of non-ceramic filler, and surprisingly, a modern tack. When the conservator returned to the drum to probe for the tack, her needle tool uncovered "what appeared to be a second surface. Painted on this second surface was the tip of a bird wing, similar in kind to the birds on the drum's exterior...the drum was so extensively restored in the past that it was literally encased in the old restoration...no original surface had ever been visible to the Museum staff or visiting public since the drum was acquired in 1967."
This discovery prompted a revised protocol for conserving the drum. The restorer's materials as well as the original clay and slip were analyzed. The conservator discussed the most appropriate new materials for reassembling the drum and the available strategies for restoration with curators and project consultants. Key issues were long-term preservation, removability ("reversibility") of materials , and how to achieve a newly-restored artifact that was both historically accurate and aesthetically pleasing.
