Abstract: A conveyor moves a series of cartridges containing undeveloped film and sender-identified mailers in correlated side-by-side relation from a loading station past a cartridge sensing station, a dual labeling station, and a plurality of discharge stations. Information sensed from each cartridge is stored in a memory and later controls the off-loading of the correlated cartridges and mailers at an appropriate one of the discharge stations from which the cartridges go their separate ways for film processing. Prior to off-loading, the side-by-side cartridge and mailer receive separate labels preprinted with correlating indicia enabling the developed film and the mailer to be correctly reunited for return to the sender.