Patent ID: 8520286

Claim:
A colored fluid comprising: at least one polar or non-polar solvent and at least one oligomeric and/or polymeric dye in the solvent, the oligomeric dye having at least one chromophore attached to one or more oligomeric chains and the polymeric dye having at least one chromophore attached to one or more oligomeric and/or polymeric chains, the dye further having a molecular weight from 400 to 100,000, solubility in the solvent of at least 5% by wt at 25° C., and a dynamic viscosity from 0.5 cPs to 2,000 cPs at 25° C., and wherein, if the solvent is the polar solvent, the colored fluid has a conductivity from about O·^S/cm to 3000 μ8Λ: η, a surface tension of 15 dynes/cm to 90 dynes/cm at 25° C., and a total content of monatomic ions with radii smaller than 2.0 A and polyatomic ions with radii smaller than 1.45 A less than 500 ppm, and, if the solvent is the non-polar solvent, the colored fluid has a conductivity less than 5×10 ˜ S/cm and a surface tension of 10 dynes/cm to 40 dynes/cm at 25° C.