PRINTER_PAPER_LENGTH: if PRINTER_PAPER_FORMAT is set to PRINTER_FORMAT_CUSTOM, PRINTER_PAPER_LENGTH specifies a custom paper length in mm, value must be an integer.
PRINTER_PAPER_LENGTH: if PRINTER_PAPER_FORMAT is set to PRINTER_FORMAT_CUSTOM, PRINTER_PAPER_LENGTH specifies a custom paper length in mm, value must be an integer.