Epson AcuLaser C1900 Reference Manual page 30

Caution:
c
EPSON Color Laser Coated Paper
EPSON Color Laser Coated Paper is designed specifically for this
printer. This media is thicker than EPSON Color Laser Paper and
produces glossier and higher quality printing. To print on EPSON
Color Laser Coated Paper, choose Coated or Coated (Back) as the
Paper Type setting. This setting is optimized for printing on
coated paper, but paper can only be fed from the MP tray.
S041383 (A4)
Note:
Duplex printing using the optional Duplex Unit is not possible when
Thick or Thick (Back) is selected as the Paper Type setting in the printer
driver.
30
Paper Handling
Do not use other EPSON media such as EPSON special
media for ink jet printers, as they can cause paper jams and
damage the printer.
Do not use the media listed above in any other printers, except
when specified in the documentation.