In the video after the break you can see some plotting that uses a pen. In addition to writing on paper, [Viacheslav] has tested this as a method of applying etch resist to a copper clad board for ...

The TPE filament acts as an etch resist, similar to methods using laser printer toner. For a substrate, [Mikey77] lists 3 options: <.001″ Pyralux material from Adafruit, which is one of the ...