Diffusion of dyes in ink-jet prints under high humidity is one of the major causes of print degradation. There is, however, no agreed method how to characterize humidity sensitivity and how to predict failure from accelerated test. The study comprises humidity degradation tests of various ink sets on polymer, porous and nanoporous IJ media. It compares different test patterns, pre-conditioning methods, test conditions, and metrics for humidity. From the extended test set, conclusion could be drawn about the media factors that are most important for humidity degradation, namely the type of colorants, the class of media or the ink vehicle. Some recommendations about test patterns and test methods are discussed.