Patent ID: 7632344

Claim:
An ink for use in combination with an ink-jet printer, comprising a mixture comprising: a colorant; a liquid vehicle containing 5.0-7.0 wt % 1,6-hexanediol and 2.0-5.0 wt % 1,5-pentanediol, together providing 7.0-12.0 wt % of said mixture, in a ratio in the rang of 1:1 (wt/wt) to 3:1 (wt/wt); at least one multivalent salt dissolved in said vehicle in a total amount of from about 1.0 wt % to about 5 wt % by weight of the ink; and an amount of imidazole, in the range of about 0.5-2.5 wt % of the ink, the mixture providing at least one of the following enhancements to said ink: improved print quality, increased decap time, pen reliability, environmental robustness of ink in pen, environmental robustness of printed ink on media, and aid in maintaining the pH of the ink in a desired range.