Temperature and voltage are 2 main parameters for printing quality control.

Temperature controls fixation of toner and voltage controls relative toner transfer amount.

So Voltage is more important for actual quality control of print out. It is related with atmosphere humidity too.

In BIZPRESS 13R printing software (LPU program), media setting provides below prinitng modes.

LPU setting
Corresponding      temperature
Corresponding      voltage
Super-low temperature   1
153
Plain
Super-low temperature 2
153
Heavy   weight
Super-low temperature 3
153
Extra heavy weight
Low temperature 1
161
Plain
Low temperature 2
161
Heavy   weight
Low temperature 3
161
Extra heavy weight
Normal temperature 1
165
Plain
Normal temperature 2
165
Heavy   weight
Normal temperature 3
165
Extra heavy weight
High temperature 1
172
Plain
High temperature 2
172
Heavy   weight
High temperature 3
172
Extra heavy weight

Each temperature (super low, low, normal, high temp) has transfer voltage group as 1, 2 and 3.

1 means plain paper. 2 means heavy weight paper. 3 means extra heavy weight paper.

So transfer voltage is 1 < 2 < 3.

For each of 1, 2, 3 group, detailed voltage offset can be adjusted in the printer engine panel.

Default is 6 and 1~15 values can be setup for each of plain, heavy weight and Ex heavy weight (1, 2, 3) group.

Press Settings button in the panel.

Select Admin Menu > Image Quality > Voltage Offset > Plain/Heavy weight/Ex heavy weight .

Choose the right paper type in LPU setting (Plain, Heavy weight or Extra heavy weight).

Setup the right offset value between 1~15.

The lower the darker color, the higher the lighter color.