One of the greatest challenges in fabrication of flexible and plastic electronics devices by printing is to obtain highly conductive patterns at sufficiently low temperatures which will not damage the heat sensitive substrates. Therefore, during the last decade, several approaches for the sintering of metallic nanoaprticles (NPs), usually silver, at low temperatures, were developed. However, the high cost of these silver based nano-inks limits fabrication of low cost plastic devices. Therefore, there is an unmet need for a low cost metallic ink with a low sintering temperature. Here we describe the formation and printing of copper based ink-jet inks. Tailoring the nanoparticles stabilization mechanism enabled the formation of a low sintering temperature ink. It is shown that the use of these ink enables the formation of various devises printed on plastic, for example, copper based electroluminescent device and RFID antennas. Furthermore, the presence of anti-oxidation agents enables to achieve highly conductive patterns stable in air for a long time.