For Mac OS X PCL Printer Driver

Select [Page Setup] from the [File] menu.

Select [A4] for [Paper Size], and the appropriate orientation for [Orientation], and then click [OK].

Select [Print] from the [File] menu.

Select [Setup] from the panel menu.

Select [Tray 1] for [Paper Source] and [Printer Setting] for [Media Weight].

Click [Print].

Printing starts.