[bitwrangler]

Has anyone used dark color 3D filament printed onto copper clad PCB as photo resist or etch resist?

It might be tricky printing PLA directly to copper clad PCB, but then you could expose the board to UV or etchant to make the PCB traces. Then remove the PLA plastic to expose the copper traces.

[scottapotamas]

Yep, variations have popped up in the DIY community over the years.

Slightly modifying/abusing the cheap DLP resin printers is more effective because they're essentially a controllable UV mask anyway.

[fainpul]

The toner transfer method uses a similar process and is probably easier. You don't need a 3D printer, but one of those laminating machines instead.

[longtimelistnr]

assumedly much much easier to buy a cheap vinyl cutter, but interesting idea