Outdoor-durable media for wide format ink jet printers has become available during the past several years. In its simplest form, an absorptive coating for this application consists of a water resistant binder and a white pigment at some optimum ratio and coatweight. A study was conducted to determine the effect of major formulation parameters on the properties of a model coating system.Among the variables examined were pigment/binder ratio, coatweight, and silica type. Over 30 silicas of widely ranging particle size and oil absorption were tested. Three important image properties were measured-ink capacity, CMYK densities, and adhesion of the dry coating. The effect of each variable alone, as well as interaction among variables was determined