Patent ID: 8430475

Claim:
An inkjet ink, comprising: a solvent system; a pigment dispersed in the solvent system having a particle diameter of at least 0.2 μm and a density of at least 2 g/cm 3 ; and a surfactant comprising at least one of polyethoxylated alcohols, alkyl-substituted betaine-type surfactants, and alkyl-substituted aminoxides, the surfactants being present in an amount less than 30 weight percent, the amount being sufficient to impart to the ink a viscosity that decreases as shear rate increases, such that the ink has a dynamic viscosity greater than 100 centipoise at a shear rate of 1 s −1 and a dynamic viscosity from 1 to 10 centipoise at a shear rate of 10,000 s −1 .