Loading A Custom Paper Size - Epson AcuLaser C4000 Owner's Manual

Make settings on the Basic Settings menu (for Windows) or
the Basic Settings dialog box (for Macintosh) in the printer
driver as shown below:
Paper Size:
Paper Source:
Paper Type:
You can also make these settings on the Tray Menu and the
Setup Menu in the control panel.
MP Tray Size (on the Tray Menu): (Select appropriate size)
Paper Type (on the Setup Menu): ExtraThk
Note:
When using extra thick paper, you cannot do duplex printing
automatically. When you want to make duplex printing with extra thick
paper, set the Page side setting on the control panel's Setup Menu to
Back or Front, then print manually.

Loading a custom paper size

You can load non-standard size paper into the MP tray as long as
it meets the following size and weight requirements:
Plain paper
44
Paper Handling
(Select appropriate size)
MP tray
ExtraThk
88.9 × 139.7 mm to
215.9 × 355.6 mm (35 × 55 in.
to 85 × 140 in.) (Weight: 60 to
105 g/m²)