A process for printing a metal wire pattern on a substrate, including: printing a first salt solution including a metal ion that will undergo a reduction half-reaction; printing a second salt solution containing a reductant that will undergo an oxidation half-reaction in contact with the first salt solution, resulting in the reduction of the metal ions of the first salt solution; and allowing the first and second salt solutions to react by a galvanic reaction, causing reduced metal ions of the first salt solution to precipitate as a solid, on the substrate.