1.    Economy Mode must be turned OFF.

2.    The Toner Setting must be set to the Darkest Possible.

3.   Please refer to the owner's manual for your printer.
Here is an example of how to select the correct settings on HP LaserJet 4000 on the Windows XP operating system: Go to the Printer Properties.  (Go to the printer folder, right click on the printer, and go to Properties.)

4.    Click on the Printing Preferences... button.

5.    Click on the Advanced... button.

6.      Under Printer Features change EconoMode to Off, and set RET to Dark.