As a result of the inherent advantage of pigment based inks over dye based inks, carbon black is now the colorant of choice for black inks in the SOHO market. There is a need for black ink jet inks which give high optical density and excellent print quality on plain paper of varying quality. In this work, a series of self dispersed carbon black dispersions were made using commercially available carbon blacks spanning a broad range of particle morphology. Inks made with these dispersions were printed on a series of 7 plain paper types of varying quality and optical densities were determined. A strong correlation was observed between carbon black particle morphology and optical density.