The quest for relevant non-print based testing of the performance and reliability issues associated with ink-jet printing devices has been a pursuit of many for over 15-years. In this talk, a micro-reactor system that has been developed for time-resolved studies of diffusion limited reactions is applied to the color-bleed assessment problem. The micro-reactor consisting of a free-falling liquid film with at least one intersecting reactant streams. The resultant film exhibits surface-area to volume ratios on a par to that of adjacent printed dots. Once calibrated for a given set of pen parameters, the micro-reactor based instrument can accurately emulate the post-print droplet environment. In so doing, new ink systems may be pre-screened for color-bleed without the time consuming need to subject the system to a print test. A film thickness of 20-to-100-um has been used to assess various ink additives for eliminating color-bleed. The instrumental technique and methodology for evaluating the color bleed susceptibility of ink parings is presented.