When you must turn merge control off to your plotter

The ability to control  the merging of colors of your plotter is a bless for most situations in your everyday drawing practice.
So in most cases you leave merge control with the"lines merge" setting selected.
When you draw building elevations in most cases your plot jobs will give you unsatisfactory results with this setting selected.
In this case you must turn merge control to the "lines overwrite" setting.
It will be more productive for you to create a new .pc3 file for this setting. One pc3 file say merged.pc3 and the other one unmerged.pc3.