Abstract: In a double-side printing control method, a printing request transmitted by a host computer is received, the printing request including print data and a given resolution of the print data. The print data is expanded to image data at the given resolution. The image data is stored in a system control part of a printing apparatus. A double-side printing is performed with the stored image data when the printing request is a double-side printing request. Before performing the double-side printing at the given resolution, it is determined whether an image memory area of the system control part that stores two pages of image data is held, and it is determined whether an image memory area of an external storage part that stores one page of image data can be held.