Epson AcuLaser C8600 Reference Manual page 198

Before you start printing in the GL/2 mode
You may need to change the following print options in your
application, depending on your output needs. Check these
settings to make sure they match the data you are trying to print.
Print Options
Paper size
Driver (plotter selection)
Pen configuration
Plot origin
Orientation
If you need to configure the printer settings, first switch to the
GL/2 emulation mode, then change the settings using the printer
driver, or the control panel menus.
Note:
Settings or data saved in the printer's RAM (such as downloaded fonts)
may be erased when you change the emulation mode.
GL Mode
Specifies whether the printer uses a direct emulation of the GL/2
plotter language, or the HP LaserJet 4 emulation of GL/2.
Scale
Specifies whether the output from the software is scaled. The scale
factor is based on the output paper size of the application.
Origin
Specifies whether the logical origin of the "plotter" is the corner
or the center of the paper.
196 Functions of the Control Panel
Settings
Printer's paper size setting
HP-GL/2 or HP-GL
Pen thickness
Center or Corner
offers landscape only
offers landscape and portrait