Epson Action Laser II - Manual (Page 51)

Testing
the Printer
2. For darker print, turn the knob clockwise.
A A
3. For lighter print, turn the knob counterclockwise.
A A
Note:
Cl Increasing the print density increases toner consumption. If
you select darker print, you may need to replace the toner
cartridge more often.
Cl When you replace the toner cartridge, turn the knob to the
default position. The knob clicks when you reach the default
position.
Testing and Connecting Your Printer 2-11