1. A printing apparatus capable of synthesizing and printing image data representing an image to be printed and image data representing a background image, the apparatus comprising: a memory that stores first image data representing a first background image of a first size; a connection unit configured to connect the printing apparatus via a network to a server that stores second image data representing a second background image of a second size that is greater than the first size; an obtaining unit configured to obtain the second image data representing the second background image that is stored in the server, by accessing the server via the network; a setting unit configured to set a condition for printing using the image data representing the image to be printed; a synthesizing unit configured to synthesize, based on the condition set by the setting unit, the image data representing the image to be printed, and the first image data representing the first background image that is stored in the memory or the second image data representing the second background image that is stored in the server; and a printing unit configured to print based on the image data representing the image to be printed that has been synthesized by the synthesizing unit with the first or second image data.