A modular printer includes a frame. A housing in which the frame is housed has an operatively upper and an operatively lower cover and defines a print media inlet at one end between the covers and a print media outlet at an opposite end between the covers. An inlet roller assembly is mounted on the frame proximate the print media inlet for feeding a web of print media into the housing. A pair of opposed inkjet printhead assemblies are mounted on the frame downstream of the inlet roller assembly to define a printing zone between the printhead assemblies. The inlet roller assembly is configured to feed the web of print media between the printhead assemblies. An exit roller assembly is mounted on the frame proximate the print media outlet to feed the web of print media from the outlet. Each inkjet printhead assembly includes a series of substantially identical printhead modules, the modules of each printhead assembly being a mirrored replication of the modules of the other printhead assembly.