Selectable modification of medium in a printer system

A computer-controlled printing system includes a host computer, an intelligent printer and an intelligent post printer processor. The print job is controlled by defining print data, printer control data and printer post processor control data in a print data stream from the host computer. The print data and printer control data are read at the intelligent printer. The intelligent printer executes the print control data to print the print data on a print medium. The printer also determines if there is post processor control data in the print data stream and, if so, sends the post processor control data from the printer to the intelligent post processor. The post processor reads the post processor control data, and executes the post processor control data to perform selected modification of the print medium. Selectable modifications of the print medium at the post processor include predetermined fixed printing of images, symbols or text, perforation of the print medium, cutting of the print medium, or user defined modifications of the print medium.