Hi John,
Don't bother trying the ultrafine point Sharpie markers. The ink
doesn't work as an etch resist... Same goes for the "huge" chisel
point industrial marker. I thought that tip would be good for going
over large copper fill areas...
I've used the black fine point Sharpie as an etch resist for
decades. For narrow traces, I've used slots cut in transparencies
as templates. I use an eraser shield and a firm eraser to clean up
the edges. Eraser shields are surprisingly difficult to find these
days; drafting (drawing by hand) must be becoming a lost art. The
last batch I bought at a craft store; poor quality with sharp edges,
but better than nothing. In a pinch, you could use a transparency
with slots cut out.
Another option is to use "Ruby" tape. This is a red transparent
tape they used to use this in the old days to layout PCB (and
integrated circuit layout) by hand. It works fine as long as you
don't have any "crossings" where etchant can get under the tape.
Yet a third option is to locate some rub-on transfers. I have some
sheets that have traces and pad patterns (but haven't seen them for
decades...).
Regards,
Dennis
--- In
Homebrew_PCBs@yahoogroups.com, "Jan Kok" <jan.kok.5y@...>
wrote:
>
> I believe there is an "ultrafine point" sharpie.
>
> I haven't tried it, but maybe you could cut two sides off a "fine
> point" sharpie with a razor blade, to get a very narrow tip.
>
> Cheers,
> - Jan
>