A mill base composition includes a compound comprising a divinyl ester of a dicarboxylic acid, a dispersing agent, and a pigment. The divinyl ester of the carboxylic acid includes from 2 to about 8 carbon atoms. The mill base composition is subjected to milling with milling beads to produce a milled mill base composition that functions as a pigment concentrate that may be added to an ink vehicle to form an ink composition suitable for use in inkjet ink devices. The milled mill base composition is particularly suited for UV curable ink compositions. A UV curable ink composition includes the pigment concentrate, one or more UV curable monomers, and one or more UV initiators.