A method and resins for use with three-dimensional printing systems and/or other energy-curing devices to create 3-D objects having electrical conductivity. The resins comprise an initiator, a photopolymerizable agent, and a nanocarbon, particularly, single-walled carbon nanotubes. The initiator, photopolymerizable agent, and nanocarbon are mixed and agitated without fully solubilizing the nanocarbon so as to maintain the electrically conductive property.