Intermec F4 - Manual (Page 42)

Intermec EasyCoder F4 – Installation & Operation IPL Version, Ed. 3 41
Chapter 6 Setting Up the Printer
Setup Parameters, cont.
Media, cont. Darkness
Use this parameter to make minor adjustments of the blackness in
the printout, for example to adapt the printer to variations in quality
between different batches of the same media quality. The value can
be setwithin the range -10 to 10% where -10 is the lightest and 10 is
the darkest. Default value is 0%.