Particles for electrophoretic displays

Electrophoretic fluids are described which comprise polymer particles having non-spherical shapes. Preferably, the polymer particles are prepd. by a process entailing polymg. a first non-aq. dispersion of at least one monomer, preferably at least one steric stabilizer, at least one initiator, optionally at least one polymerizable dye, and optionally at least one charged comonomer in a non-aq. solvent; optionally cleaning the resulting polymer particles; forming a second non-aq. dispersion of the polymer particles in a non-aq. solvent; adding to the second non-aq. dispersion at least one monomer having a partition coeff. different from the partition coeff. of the non-aq. solvent, preferably at least one steric stabilizer, and at least one initiator; polymg. the second non-aq. dispersion; and optionally cleaning the resulting polymer particles. Electrophoretic display devices comprising the electrophoretic fluids and the use of the electrophoretic fluids in the prepn. of monochromatic, bichromatic, or polychromatic electrophoretic devices are also described.