London-based Bare Conductive makes paint that conducts electricity. It's called electric paint and it can be used on a variety of surfaces including paper, plastic, wood, cardboard, or glass.

A general purpose shielding spray for use on plastic electronics enclosures. Consists of a tough, durable acrylic base pigmented with high quality silver coated copper flakes.

[Clem] paints the plastic parts to grant them conductivity. Graphite paint didn ... wasn’t up to the task. Copper plating is often used as a step to make a part conductive so you can then ...