An ink-jet ink composition for ink-jet printing and a method using the same is disclosed, the ink composition comprising an aqueous liquid vehicle, at least one zwitterionic surfactant; and at least one amphiphilic dye, said at least one amphiphilic dye comprising a plurality of amphiphilic dye molecules,...http://www.google.com.au/patents/US5935309?utm_source=gb-gplus-sharePatent US5935309 - Ink-jet inks for improved print quality
