Check the Page Size
This printer performs automatic cleaning when necessary to keep printouts clean. A small amount of ink is ejected for cleaning. Although ink is usually ejected on the ink absorber, it may be ejected on the paper if you load paper larger than that specified with the printer driver.

Click 'File', and then click 'Print' from the application you are using. Ensure that the correct printer is selected and the 'Page Size' setting in the printer driver matches the size of the paper loaded in the printer.
In versions older than Mac OS X 10.5, Check the Page Setup dialog box. Open the Page Setup dialog box by clicking File and selecting 'Page Setup' from inside the application being printed from.