Non-transitory computer-readable storage medium storing instructions implementing supporting program

A non-transitory computer-readable storage medium for an information processing device, the information processing device including a controller, the non-transitory computer-readable storage medium storing computer-executable instructions for implementing a supporting program for a printer connectable to the information processing device, the printer including trays and allowing specification or detection of a size of a sheet to be loaded into each of the trays, the supporting program that, when executed by the controller, causes the information processing device to perform:

• receiving a scaling factor, the receiving including displaying a setting screen on a user interface of the information processing device to allow specification of the scaling factor through the setting screen,
• wherein the information processing device has an operating system including a universal printing program, the information processing device is incorporated with an application program,
• wherein, in response to the universal printing program receiving, from the application program, a print instruction that causes the printer to perform printing, the supporting program, when executed by the controller, causes the information processing device to perform:
• determining an output size based on a size of an image to be printed included in the print instruction and the scaling factor;
• obtaining sheet sizes specified for the respective trays of the printer or detected in the respective trays;
• identifying an appropriate tray from the trays, the appropriate tray being specified with a sheet size within a range approximately equal to the output size or being loaded with a sheet whose size is within the range approximately equal to the output size;
• obtaining a scaled image, the scaled image being obtained by scaling the image to be printed based on the scaling factor;
• and
• causing the printer to print the obtained scaled image using the appropriate tray of the printer.