Patent ID: 8690308

Claim:
An inkjet ink comprising water, colorant, and a dynamic surface tension agent at an effective concentration such that the ink has a dynamic surface tension DST 1 sec at 1 second universal surface age, a dynamic surface tension DST 10 sec at 10 seconds universal surface age and a dynamic surface tension DST 20 min at 20 minutes universal surface age, where DST 20 min is less than each of DST 1 sec and DST 10 sec , and the difference between DST 10 sec and DST 20 min is greater than 9.2 mN/m at 21° C. or the difference between DST 1 sec and DST 20 min is greater than 15.5 mN/m at 21° C., and wherein the static surface tension of the ink is less than 50 mN/m.