A printing system includes an optical sensor that reads a plurality of order sheets at least selecting images to be printed and printing sheet types, a printing specifying unit that specifies the images and printing sheet types selected by the order sheets on the basis of an output from the optical sensor, a reader that reads image data of the images selected by the order sheets from a recording medium, and a printer that prints the read image data on types of printing paper which correspond to the printing sheet types selected by the order sheets, wherein after the optical sensor reads the order sheets, the printer performs batch printing based on the images and printing sheet types selected by all the order sheets.