This invention relates to electrophoretic displays having improved performance. The threshold promoter of the present invention may induce or significantly enhance the threshold effect by improving the particle-particle interaction and/or the particle-electrode interaction. The promoter may be present in the system as a soluble or micelle molecule in the electrophoretic fluid or an adsorbed or chemically bonded molecule on the surface of particles. The use of such a threshold promoter does not show a detrimental effect on the display switching rate.