Excellent test. I did something similar and was amazed at some results.
I now use a black 'Laundry marker' available here in the UK from W H Smiths a newsagents chain store.
It works quite well but as with all of the markers you cannot over etch. It is reminiscent of the Dalo PCB pen in that the light tracks look multicoloured under certain light conditions. (Oh how I miss the Dalo pen ! )
For the US folks maybe something similar is available.
Rob G4NQX
I now use a black 'Laundry marker' available here in the UK from W H Smiths a newsagents chain store.
It works quite well but as with all of the markers you cannot over etch. It is reminiscent of the Dalo PCB pen in that the light tracks look multicoloured under certain light conditions. (Oh how I miss the Dalo pen ! )
For the US folks maybe something similar is available.
Rob G4NQX