ANSI Standard IT9.9-1990 is one methodology commonly recommended for predicting dark storage print life for color photographic materials. This methodology focuses primarily on measurement of changes that occur due to temperature at one relative humidity (50% ± 3%). Of greater concern for dark stability of inkjet prints, however, is humidity levels that are higher than 50% RH, especially as consumer usage of inkjet continues to expand all over the world. Ink/media combinations exist today that respond almost immediately to humidity in excess of 50% RH, even at ambient temperatures, and these instabilities are a major concern for both manufacturer and user. In addition, the effects of elevated humidity on inkjet prints vary widely between different ink/media combinations. Several quantitative measures are necessary to adequately describe the resultant behaviors. The objective of this paper is to begin to explore these relationships providing a foundation of understanding that will ultimately lead to a robust model that correctly predicts the image quality degradation as a result of exposure to variable dark keeping conditions.