Using commercially available software (Discrete Coulomb Interactions Software from Munro’s Electron Beam Software Ltd.) we have investigated image broadening as a result of stochastic interactions for projection systems. We have derived empirically, design constraints applicable to ion and electron projection systems and used them to analyze system designs suggested in the literature. We conclude that for many of the suggested designs stochastic interactions will prevent useful throughputs from being achieved. Finally, we discuss system design approaches which are necessary for a successful high-throughput, high-resolution image projection lithography system.