Ten microfilms were processed in a nonrecommended process in which the final wash was spiked with seasoned fixer to give various amounts of residual thiosulfate in the films. The samples were incubated at several temperatures and 60% relative humidity to try to predict the behavior of the films at 24° C and 60% RH storage. Most of the films showed very little change even at high residual thiosulfate levels. The one possible Arrhenius prediction showed the films did not change even beyond the proposed archival criteria for about 1500 years. These results are available to the Task Force of ASC subcommittees PH 1-3 and PH 4-2 to consider during the revision of the image stability portion of the proposed standards on microfilms. These standards will probably be modified to allow more residual thiosulfate ion of the archival criterion. A long-term criterion will also be added. -- AATA