A lithographic printing ink contains an ester-modified carboxyl-containing copolymer as a pigment dispersant. The ester-modified carboxyl-containing copolymer is the reaction product of a long chain alcohol and a styrene maleic anhydride copolymer, wherein at least 35% of the carboxyl groups of the styrene maleic anhydride copolymer are esterified. The ink further includes a solvent selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, and mixtures thereof; a modifying oil; a liquid carrier resin; and a pigment.