A printing module includes a first imaging device and a slot for accommodating an optional second imaging device. An ink supply module includes a slot for accommodating an optional drying/fixation apparatus, and a second ink supply device. Also, the ink supply module and the printing module include ink inlet/outlet ports such that the optional second imaging device in the printing module, if present, can be supplied ink from the second ink supply in the ink supply module when the printing module and the ink supply module are combined to form a printer.