A dispersion as in claims 1, 2, 3, 4 or 5, wherein said colorant is an electrically photosensitive material selected from the group consisting of:(a) aromatic vinyl compounds having condensed heterocyclic nitrogen-containing nucleus; (b) aromatic vinyl arylamine compounds; (c) aromatic vinyl compounds having a heterocyclic nucleus; (d) merocyanine and benzylidenes having at least one nucleus selec