Dell 2350D User Manual page 39

From this You can:
menu:
NOTE: This setting is available only on the PCL emulation driver,
PostScript emulation driver, or on the printer Embedded Web
Server.
Gray Automatically adjust the contrast enhancement applied to images.
Correction
Auto*
Off
Auto applies different gray values to each object on the printed
page.
Off turns off gray correction.
Brightness Adjust the gray value of printed images.
-6 to +6
0*
Contrast Adjust the contrast of printed images.
0–5
0*
* Factory default setting
Utilities Mode
Mode Menu
Utilities
Use the Utilities menu to troubleshoot printer problems.
1. From the menu list, use the Arrow buttons
2. Press the Select button
3. Press the Right Arrow button
the Select button
4. Use the Arrow buttons
5. When the setting you want appears on the display, press the Select button
Utilities Mode Main Menu
Mode Main Menu
Hex Trace
.
until the heading you want appears on the display, and then press
.
to scroll through the available menu items.
to scroll to the Utilities menu.
to save the setting.