We report a method of converting non-conductive plastic surfaces into conductive by coating either aluminum or aluminum-carbon black containing enamel pastes onto acrylonitrile-butadiene-styrene (ABS) plastics to create aluminum-seeded surfaces for a subsequent copper deposition. Through a simple electroless procedure, copper ions were reduced on the Al seeds and deposited on the ABS surface to develop a conductive layer in about 10-min deposition time. We demonstrate that addition of carbon black particles to the pastes shorten the time to reach the maximum conductivity and enhance the adhesion of electrolessly deposited copper layer to the ABS substrate surface. The electroless copper deposition process developed in this study may open up a new route of plating on plastics (POP) for printed circuit boards, electromagnetic interference shielding, and many other applications.