This paper gives an overview of the various factors affecting the permanence of digitally-printed photographs.1 Accelerated test methods are discussed, with emphasis on light stability tests specified with past and current ANSI and ISO Standards, future ISO Standards, and the “de facto” test method standards now widely used in the imaging industry, such as the predictive “Display Permanence Rating” test method developed by Wilhelm Imaging Research and the predictive stability test methods employed by Eastman Kodak for evaluation of Kodak Ultima Picture Paper (ColorLast, 2003 type). Light stability data for representative products evaluated with these two “de facto” test methods are given, and the major factors that account for the large differences in outcomes are presented.The potentially large impact of reciprocity failures in highintensity accelerated light stability tests is illustrated with longterm test data for an inkjet paper printed with dye-based inks. The importance of the selection of the spectral power distribution of the illumination source employed for accelerated light stability tests is emphasized.