Electrophoretic mobilities of copper phthalocyanine (CuPc) particles dispersed in Isopar G™ are reported. The mobilities were measured as a function of particle charging agent (PCA) concentration using Phase Analysis Light Scattering (PALS). The role of Particle Stabilizing Agents (PSAs) at the particle surface was also investigated. An equilibrium site binding model can describe the experimental data adequately. Conductivity measurements and adsorption isotherms facilitate an overall description of particle charging in these systems.