We create a computer based numerical model to predict the color spectra of printed patches on dry toner electrophotographic printers. The goal of this research is to obtain a simplified model describing the input-output behavior of the printers based on the physical characteristics of the different printing process steps and the interactions between them. This leads to a better understanding of the factors that have an impact on printing quality. Furthermore, by modeling the non-linearities of the electrophotographic process, the prediction model will allow the creation of device calibration data with a minimal effort.In order to avoid the additional optical non-linearities produced by light reflections on paper (dot-gain), we have limited the present investigation to transparency prints. In its current version, the proposed model is capable of predicting the transmittance spectra of a printed monochrome wedge down to a mean deviation less than CIELAB ΔE*_ab = 1.5.The proposed simulation incorporates sub-models of the electrophotographic process [1, 2] shown in Fig. 1, such as the exposure of the photoreceptor, the generated electrostatic field, the toner's charge and diameter distributions, as well as the transfer and the fusing steps.