As reproduction of digital images with ink jet printers becomes increasingly popular, so too does the demand for images which are lightfast and meet customer expectations. Manufacturers of ink jet inks and media need light stability test methods using accelerated laboratory test apparatus that can better help them predict the durability of their product. Accelerated laboratory testing provides reproducible results for materials exposed to specific sets of conditions. It is intended to determine material durability and improve material formulation.The first part of the paper provides a history of accelerated laboratory testers, including carbon arc, fluorescent UV, and xenon arc. The inherent strengths and weaknesses of each type of tester will be reviewed. Background is also provided on sunlight and spectral power distributions.The second part of the paper reports on (1) publication of new ASTM performance-based specifications for laboratory weathering test apparatus; (2) recent standards activities for lightfastness testing of printing inks and artists' materials; and (3) development of appropriate test methods suited to products and their end-use environments.