Ambient levels of ozone have been reported to be a factor in the dark stability of ink jet photographic prints. Current practical tests utilize a relatively high concentration (5–10 ppmv) of ozone for short periods of time at ambient temperatures to predict what might occur for longer exposures at lower concentrations. However, ambient ozone levels are typically well under 0.1 ppmv (100 ppbv). In this article we describe a custom built ozone chamber with which we are able to explore the effects of chamber design, flow rate, relative humidity, and ozone concentration on the kinetics of fade for ink jet photographic prints.