Abstract: Photosensitive composition for use in photoelectrophoretic imaging systems. The particulate component of this composition includes vanadyl phthalocyanine pigment particles which have been treated with a phenazine-type dye and a mixture of polymeric materials consisting essentially of at least one polymer having structural units of the formula ##STR1## WHEREIN Z is a pendant group of the formula ##STR2## X is a substituent substantially incapable of withdrawing electrons from the electron rich pyridinyl moiety;m is a whole number from 0 to 3; andn is a whole number in excess of 25;And, at least one polymer having structural units of the formula ##STR3## wherein X is vinyl, alpha alkyl substituted vinyl, or alkyl of 1 to 4 carbon atoms, andY is vinyl, alpha alkyl substituted vinyl or alkyl of 1 to 4 carbon atoms with the proviso that when only one of either X or Y is vinyl or alpha alkyl substituted vinyl per structural unit.