Abstract: A multicolor electrostatic printing machine having processing components to produce a copy of a color original comprising color separation masters which represent each color of the original and move along an exposure station as they are exposed by a flash assembly. Latent images of the masters on a photoconductor are developed at a development station, and the developed images transferred in superposition to support paper at a transfer station. Digital logic circuitry ensures that the latent images are correctly placed on the photoconductor, such that the images are superimposed, by varying the timing of the flash assembly in dependence on the relative positions of the moving masters and the support paper.