Canon BJC-3000 Series User Manual page 120

Changing the page size (for regular paper sizes)
1
Click the Page Layout tab.
2
Click the down-arrow in the Page Size box, then select the appropriate
page size from the pull-down list.
Note
Depending on the application program you use, the Page Size box may be
grayed out and unusable. If this occurs, click the Cancel button to close the
Printer Properties dialog box. Then open the Printer Properties dialog box
from the Start menu and try again.
Opening the Printer Properties Dialog Box
Getting to Know the Printer Driver
Using the Windows Printer Driver 120