With the dramatic increase in the prevalence of photoprinting using ink jet printers in recent years, much effort has been made to increase the longevity of the resulting prints. Many of these phenomena, unfortunately, require long-term testing in order conduct an accurate assessment. Much of the testing to date has been purely empirical in nature, allowing little improvement from a rational perspective. To overcome these limitations, this paper introduces a simple model of the light induced fading of magenta dye-based inks on polymer-coated photo media that represents fading as a two step process. Using this model, fade data collected in as little as nine days may provide accurate predictions of these ink/media combinations out to approximately 20 years of simulated fading. In many instances, the model can be further simplified. This analysis allows the definition of a "light fade factor" for both the ink and media which may serve as a useful figure of merit to facilitate the rapid qualitative comparison of ink and media formulations.