In class we experimented with two types of board making. Aisen hacked inkjet cartridge with a nano-technology silver ink to print circuits.
However the process I used was the sharpie and acid to create my board.
Using the diagrams on the board I drew my board out, soaked it for about forty minutes and began to solder my components.
There were a few issue with my board especially with thin circuit lines, but they were easily fixed with solder.
One issue I had was that instead of the distance between my finger tip and pencil tip changing the pitch, the pitch grew slowly higher regardless of the distance until it went silent/supersonic. I’m assuming something with the capacitor not releasing the charge, or maybe something solder backwards? Regardless, it does work sometimes… I’ve since used it in Japanese class.