HP 2-Pen Graphic Plotter - Multiple Pen Colors
How to use more than two pen colors in a plot.
The best way to use more than two colors in a plot is to have software that will stop plotting when a new color pen is required. You can then change the pens and continue plotting. You can also use the front panel to pause a running program allowing pen substitution in multicolor applications or, try plotting in layers if the application allows.
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