Abstract: An ink jet ink for thermal ink jet point-of-sale printers is provided, comprising: (a) a vehicle comprising (i) 5 to 10 wt % of a drying agent selected from the group consisting of 1,2-hexanediol and 1,2-pentanediol, (ii) 15 to 32 wt % 2-pyrrolidone, (iii) 15 to 37 wt % of at least one humectant, and (iv) the balance water; (b) 0.5 to 10 wt % of a water-soluble dye; and (c) 0 to 3 wt % comprising buffers, corrosion inhibitors, surfactants, biocides, polymers, pigments, and binders, with the proviso that the total amount of surfactants is 0.1 wt % or less, based on the total ink composition. In particular, the ink jet ink is employed in combination with a printhead having a nickel orifice plate through which droplets of the ink are expelled onto a print medium. The ink jet ink composition is environmentally friendly, reliable, and fast drying, on the order of 300 msec and less. Further, the ink composition exhibits minimal puddling on the nickel orifice plate, leading to improved print quality.