Homebrew PCBs

> 1. Clean PCB blank and spray with high temp black / dark paint.
> 2. Laser at low power / high speed to burn away paint around traces 
> (isolation) or raster for removal of larger areas.
> 3. Etch.

I have tried this with a range of different paints and the problem I 
have found is that the paint doesn't burn off cleanly which interferes 
with the etchant. I haven't found a good way of removing the residue 
without removing the paint as well.