A printing apparatus comprising a flexible photoreceptor belt movable past a series of image processing stations, and driven around at least two support rollers, has a developer module having at least two alternately selectable stationary developer housings positioned within the run of the photoreceptor belt between the support rolls together with an articulating backup blade to alternately urge the photoreceptor belt into development engagement with one of the stationary developer housings to develop an electrostatic latent image formed on the belt.