After changing the paper size, specify the paper size using the control panel.
Press [Home] () at the bottom of the screen in the center.
Flick the screen to the left, and then press the [User Tools] icon ().
Press [Tray Paper Settings].
Select a tray from [Tray Paper Size: Tray 1] to [Tray Paper Size: Tray 3] for which you want to change the paper size.
Select the loaded paper size, and then press [OK].
Press [User Tools] () on the top right of the screen.
Press [Home] () at the bottom of the screen in the center.