A non-transitory computer readable storage medium storing computer readable instructions that are executable by a computer is provided. The computer readable instructions, when executed by the computer running the image processing program, cause the computer to generate an image to be printed on a particular type of printing medium in a printing apparatus, control a display to display the generated image, set a printing mode to one of a regular printing mode and a trial printing mode, in the regular printing mode, generate print-image information to be used in the printing apparatus to print the image on the particular type of printing medium, and in the trial printing mode, generate print-image information to be used in the printing apparatus to print the image on another type of printing medium different from the particular type, and transmit the generated print-image information to the printing program.