In this paper, the authors present silver nanoparticles ink synthesis targeting conductive patterns for micro fabricated devices by ink jet printing technology. The well dispersed nanoparticles ink was composed of silver colloid with an average particle diameter less than 10 nm. These nanoparticIes were protected by a capping layer of poly(N-vinylpyrrolidone) (PVP) even at silver concentration of 20 wt percent. Stable aqueous inks were formulated by using a combination of solvent and co-solvents and under vigorous stirring. Various factors affecting the adhesion between the ink and the substrate were investigated, such as solvent and co-solvent content. The ink containing 20 wt percent silver has a viscosity of about 9.5 cP and a surface tension of 32 to 36 mN m-1 at room temperature, meeting ink jet printer requirements. The ink stored under ambient conditions was stable against aggregation for more than one month. Silver nanoparticles patterns have been successfully printed on various substrates.