The article aims to optimize the inkjet printing properties to realize highly conductive and mechanically stable printed patterns on the Polyethylene terephthalate (PET) substrate. The key printing parameters such as drop spacing, the number of printed layers, and sintering temperatures were investigated. The test specimens were printed using silver nanoparticle ink and Dimatix 2831 inkjet printer. Then, the printed samples were characterized by electrical conductivity, bending, and adhesion tests. The Analysis of Variance (ANOVA) analysis showed that the number of layers and sintering temperatures were significant factors (p<0.05) affecting electrical conductivity. The optimum printing parameters for the PET substrate were found to be 20 mu m drop spacing, three layers of printing, and 120 degrees C sintering temperature for 30 minutes. The measured optimum resistivity was found to be 5.25 mu Omega-cm. The repetitive bending and adhesion test and ASTM tape test indicated good mechanical stability. (c) The Author(s) 2019. Published by ECS.