Inkjet printing of electrically conducting tracks often faces the requirement to restrict the temperature/time range of postprocesses in order to allow a wider choice of substrate materials. Thermal oven curing of inkjet printed silver nano-particle inks typically requires temperatures well above 100 °C for several minutes, while laser-based thermal treatment uses higher peak temperatures during shorter periods.A ‘chemical’ post-treatment with halogenides in a ‘semi-dry’ process, which was performed at room temperature or slightly elevated temperatures, was demonstrated to efficiently cure inkjet printed silver nano-particle inks, and to produce electrical conductivities close to that of pure silver. The tests were conducted on several coated paper grades and the chemical post-treatment appears especially well suited for applications in paper-based packaging, where electrical devices add functionality or ‘intelligence’ to packaging.