Apple LaserWriter 12/640 PS - Manual (Page 73)

3 Choose a default paper size for the multipurpose tray from the pop-up menu.
The Print dialog box provides the Auto Select option, which allows the printer
to draw paper from any paper source that holds the correct size paper.
Similarly, the automatic tray switching feature allows the printer to select
another paper source that holds the correct size paper when a paper source
runs out. However, the printer is not able to detect the size of paper you may
have placed in the multipurpose tray, so you must tell it. If the paper size for
the multipurpose tray is the same as the paper in the standard paper cassette
(and automatic tray switching is turned on), the printer automatically uses the
multipurpose tray as a paper source.
4 Choose a default envelope size for the envelope tray from the pop-up menu, if the
envelope cassette option is installed.
5 Choose printing on one side or both sides of the paper from the pop-up menu.
If you want the binding orientation along the side of the paper (like in a book
or magazine), choose “two-sided, no tumbling.” If you want the binding
orientation along the bottom side of the paper (like in a calendar), choose
“two-sided, with tumbling.”
Note: You must have the optional duplex printing unit to print on both sides
of the paper.
If you want to You need this much printer memory
Turn on PhotoGrade or use the 12 MB
duplex printing option
Turn on PhotoGrade and duplex 20 MB
print on all size paper (except legal)
Turn on PhotoGrade and duplex 24 MB
print on all size paper (including legal)
48 Chapter 2