Try this
http://mynock.dhs.org/pcbmilling/--- In
Homebrew_PCBs@yahoogroups.com, "onenastyviper"
<oneNastyViper@h...> wrote:
>
> Hi guys, I have now set my plotter up for scratch-etching (carbide
> tipped modified plotter pen)
> I am not able to understand how to get the plotter to scratch though
> a resist to expose copper to etch away and isolate tracks.
> I have Eagle (free version) and Proteus PCB software packages...
> What is the process to go from a PCB in gerber or hpgl to an HPGL
> code file that will trace the outlines of the tracks??
>
> thanks, PK