Homebrew PCBs

I'm not looking to plot a massive circuit.
I just wanted to find the right ink for a .5mm technical pen
or
fine point marker
that would draw a trace on copper and resist acid etching.
FOR
touching up any missing or damaged TONER TRANSFERed traces.

I found that standard sharpies dry out and stop depositing ink.
I found that STAEDTLER LUMOCOLOR permanent 313 BLACK and GREEN ink
worked great...flowed freely..resisted etching......
so
I thought it would be interesting to see if there was an indutry standard
.5mm drafting pen ink that performed the same acid resist.



On 11/22/2016 04:44 AM, 'Dave Wade' dave.g4ugm@... [Homebrew_PCBs] 
wrote:
>
 > recommended using a red plotter ink made by Stadler (sp?) which provided
>
> > very good etchant resistance.
>
> I have an HP7475 plotter. I have once used a much modified RED 
> Lumicolor pen to make one test board, and found the etch time fairly 
> critical, but I would say it was usable with some tunning.
> I would say it would probably work with refinement but a fine pen 
> takes a long time to fill the lands on the plotter.
> This must be around 2 or three years ago.
>