3D conductors are developed by inkjet printing a UV curable ink composed of oil-in-water emulsion combined with a dispersion of silver nanoparticles. Upon UV radiation by LED light the droplets immediately polymerize and form solid structures with embedded silver nanoparticles. The unique composition of the new ink enables sintering of the silver nanoparticles at room temperature by contact with NaCl solution, leading to a conductivity of 1.9 × 10 6 S m-1 while maintaining the 3D structure. The aspect ratio for photo-polymerized printed lines is more than 10 times larger than that of non-irradiated lines. The emulsion-dispersion new inks are potential materials for 3D fabrication of conductors and other functional materials in printed electronics.