Since the current blanking process does not match the requirements of automatic offline blank separating machine, a method of imposition process for achieving full-size offline automatic blank separation is put forward. Based on the working principle of full-size offline blanker, the automatic separation requirements of the finished products were given, and Adobe Illustrator and TongYin PDF Expert software were used to complete the product imposition layout. The practical case analysis results show that the application of this method achieved nearly two times’ increase in the work efficiency and two-thirds decrease in the labor demand compared with manual blank separation. It also doubled the productivity of offline blanker with less than 5 minutes’ change over time for different jobs compared with offline stripping machine. It could provide a new solution for achieving automatic blank separation for the commercial imposition printing, with significant efficiency improvement and cost reduction.