5 CONCLUSIONS

Kodak has been conducting natural-aging tests on photographic films and papers for about 20 years. A long-range testing program contains hundreds of jobs run (for the most part) on production materials through standard processes (the use of proper chemicals at specified conditions). A study of four examples (two films and two papers) shows good correlation with practical experience and Arrhenius testing. Even in the most severe condition—26�C/60% RH—the black-and-white film KODAK PANATOMIC-X shows no detectable changes after 19 years. Two of the color products—KODAK Dye Transfer Paper, and KODACHROME film—show no significant changes after more than a decade of keeping. KODAK EKTACOLOR 37 RC paper shows losses in cyan dye. It takes approximately 12 years for a 10% loss at 24�C/40% RH, a conclusion that approximates the predictions at the same conditions from years of Arrhenius testing. KODAK EKTACOLOR Plus Paper is predicted to require 36 years for the same dye loss. These results are only an introduction to this important topic and the data associated with it. Although our natural aging data cannot be generally made available, a series of future papers about other photographic products are planned to report more of our findings.

ACKNOWLEDGEMENTS

The authors wish to thank the other acting members of Team Tortoise—Deborah Chase, James Nolan, and Barbara Mule. This work represents the efforts of many people at Eastman Kodak Company, most of whom have long since retired. The results of their considerable foresight and efforts have yielded the valuable data which we have described in this paper.