A method and system for processing data indicative of pages of mailpiece content material, and for printing pages “on demand” for use in a mailpiece inserter. The method comprises the steps of: (i) transmitting data from the application software to a print processor along read and write paths and (ii) activating one of the write and read such that when one path is activated the other path is inactivated. The data is then rendered into a print control language (PCL) compatible with a printer integrated with the mailpiece inserter and printed for use therein. The method and system mitigates printing errors by eliminating synchronous access to the same data location within the spool file, i.e., by the application software/spooler along the write path and the print processor along the read path.