CAIG LABORATORIES CW100P CONDUCTIVE INK, PEN, 4G

Be careful with buying 2x it may only be a 1-pack. Takes a LOT longer than 10 minutes to dry, it can slightly spread outwards from your desired line so be careful applying much at once if you're working with a circuit board.

I received only one of the 2 Pensacola that I ordered. Luckily it was enough to complete my project. The circuit writer Pensacola is a very handy product.

Does not work. Leaves a white trail that does not conduct at all.