"Conductive ink" refers to a type of ink that contains materials that conduct electricity. It can be used to draw or print electrical circuits and components on surfaces such as paper or fabric. Full definition
So many people talk about 3D printing an iPhone, when all you can actually do is print a few limited components of one,» says Matt Johnson, founder of London firm Bare Conductive, which makes conductive ink for hobbyists. (newscientist.com)