Configuring trays for custom paper
Some software programs and printer drivers allow you to specify custom media-size dimensions. Be sure to set the correct media size in both the page setup and print dialog boxes. If your software does not allow this, specify the custom media-size dimensions at the control panel. See System Setup menu for more information.
Use the Any size size setting when the selected media does not exactly match the size of the paper specified in the document you are printing. If no source tray is specified, the printer looks first for paper that exactly matches the document, and then it looks for and prints from a tray set to Any size or Any type.