7 7. CONCLUSIONS AND RECOMMENDATIONS

Based on the examination and preliminary tests conducted on the samples of records made on polyester film, the following recommendations are suggested:

1. Once the images on polyester film begin to deteriorate, the damage is irreversible and continues with time. Therefore, it is crucial to capture the information by transferring it to a more stable medium, such as silver line photography or microfilm.
2. Storage conditions need to be carefully designed. Temperatures of 50�F (or lower) and low humidity will extend the life of records. A high level of RH proved to have the most significant impact on image stability. If enclosures need to be used, only polyethylene, polypropylene, or clear polyester film are recommended. Records created by different imaging techniques should be stored separately to prevent chemical interaction between the different types of materials.

The evidence presented here is intended to serve as a base for more extensive research on the complex problem of deterioration of images created on polyester film. The authors believe that evaluation of the imaging systems that were encountered in the course of this work and the analysis of deterioration processes will alert the curators and users of the records to the problems of film permanency and the need to adequately care for records on polyester film.

ACKNOWLEDGEMENTS

The authors wish to acknowledge the assistance of Charles A. Long, instrumentation specialist, Chemistry Department, Johns Hopkins University, Baltimore, Maryland; and Douglas Nishimura, Image Permanence Institute, Rochester Institute of Technology, for their constructive criticism and suggestions; Susan Page, senior conservator, and Kitty Nicholson, supervisory conservator, National Archives, for sharing information on their drafting film research. The authors are appreciative of the various company officials for answering questions and sharing information on their processes, materials, and research. The reader should be aware of the difficulties, countless hours, and hard work that go into ferreting out such proprietary information. Not every company is generous in its willingness to share information that may be so necessary to the conservator. Thus, the authors are indebted to those who were so willing to share this information. They include Paul Stouffer, government business manager, Imaging Systems, Agfa Division, Bayer Corporation, for valuable information on Agfa processes, films, and imaging systems; Bill Sparwasser and Robert Ford, Reprographic Technologies, Baltimore, Maryland, for assistance with identification of commercial reprographic systems and a comprehensive tour of the plant; Christine Montgomery, president, Annapolis Copy Center, Inc., Annapolis, Maryland, for information on commercial reprographic processes. The authors would also like to acknowledge Rafal Szczepanowski, RIT School of Industrial Design, for computer graphics illustrations; Ann N'Gadi, Research Library, Smithsonian Center for Materials Research and Education, for her patient compliance with numerous literature search requests; and Betty Seifert, chief conservator, Maryland Archeological Conservation Laboratory, Jefferson Patterson Park and Museum, St. Leonard, Maryland, for allowing access to the examination and printing unit of a Nikon/Hitachi digital signal processor; and the Maryland state archivist for enabling presentation of the results of this work at the 1996 AIC Annual Meeting in Norfolk, Virginia.