Provided are a method, system, and program generating user defined marking settings to print marks to control post-processing devices. A user interface is generated to enable user input to define at least one marking setting comprising a name of the marking setting, a dimension of a marking, and a location of the marking on the print medium. Marking settings control a printer to output markings on a print medium. The outputted markings on the print medium control at least one post processor device to perform post processing operations on the print medium. User input is received from the user interface defining at least one marking setting. The user defined at least one marking setting is stored with an existing set of marking settings to control the printer.