5 CONCLUSION

Evaluating conservation research is especially challenging because of the diversity in research design, test conditions and procedures, and the interpretation of results and recommendations. The importance of good research design—requiring a limited area of investigation, reduction of variables, thorough characterization of samples, and familiarization with the chemistry of materials in order to understand the advantages and disadvantages of selected test procedures—cannot be overemphasized (Burgess and Binnie 1990). On the other hand, procedures are continually being developed and refined to improve instrument sensitivity and the quality of information, and this may account for apparent inconsistencies in research. For instance, there is a need to codify accelerated aging conditions such as temperature, relative humidity, time, sample mounting techniques, and air-to-sample volume ratios, to determine the best modes for color measurements (e.g., the use of whiteness, brightness, reflectance, or CieL∗a∗b∗ or Yxy modes, relative to standard or target values, and recorded as difference or absolute measurement); and to further improve and adapt chemical and mechanical tests. Consequently, because of the constant evolution of procedures, it is imperative that all data be recorded and available for reinterpretation. Conservators must evaluate conclusions and recommendations in the context of the specifics of a particular research project, and conservators alone bear the responsibility for determining how findings apply to their own special cases. Researchers can supply only increments of information, which often generate more questions, and research findings can only aid, not replace, a conservator's good judgment.

ACKNOWLEDGEMENTS

I would like to thank the authors and speakers who allowed their work to be summarized in this article and the AIC Conservation Science Task Force, whose survey of research areas of interest to paper conservators reflected many of the topics covered. I would also like to acknowledge the numerous other conservators, interns, and conservation scientists who shared the following information about ongoing projects at their institutions. The research team headed by Chandru Shahani at the Library of Congress continues with projects on mass deacidification with diethyl zinc, the optimum alkaline reserve for paper, and the amount deposited by aqueous versus nonaqueous deacidification methods as well as on the diffusion of gases and acids in polyester film encapsulation and the effect of aging specimens in polyproylene enclosures as compared to humid aging. Susan Lee Bechtold reports that the National Archives is researching stable plastic enclosures for shrink wrapping damaged text blocks as well as the aging characteristics of adhesives, paper, film, tapes, and disks. At the Conservation Analytical Laboratory, Smithsonian Institution, Timothy Vitale is investigating the effects of drying on paper, having organized a seminar including work by Jon Arney, who is developing a system to measure changes in surface texture of paper. At the National Gallery of Art, Shelley Fletcher and Elmer Eusman are expanding on Pia De Santis's exploration of solvent residues and brown-line effects in naturally aged papers. The effect of aqueous light bleaching on sized rag paper is being continued by Terry Schaeffer as a collaborative effort with the Los Angeles County Museum of Art and the Getty Conservation Institute. At the Art Conservation Program, State University College at Buffalo, Irene Br�ckle is investigating the effects after aging of increasing concentrations of aluminum sulfate in gelatin sized papers. Finally, I would like to thank the many interns and colleagues who participated in projects mentioned above or reviewed and critiqued the manuscript, including Konstanze Bachman, Katherine Eirk, Eleanor McMillan, Nancy McRaney, Alan Postlethwaite, Olga Souza, Chris Tahk, Charles Tumosa, and Lambertus van Zelst.