The authors present a new approach for modeling toner transfer in xerographic printing. Our formalism combines a new three-dimensional (3D) stochastic fiber network model of paper, a 3D model of electrostatic, and contact adhesion forces acting on toner particles in xerographic printing. Our modeling platform allows the authors to study the relative importance of paper surface and mass density variations in establishing the electrostatic and contact adhesion forces crucial in controlling toner transfer efficiency during xerography. Simulations of xerographic printing are used to show that state of compression of the paper surface in the print nip is critical in controlling the distribution of toner onto paper. This is quantified by showing how the paper surface controls the distribution of both the electrostatic and contact adhesion forces that draw toner to paper. In contrast, paper formation, a traditional index of paper quality in the paper industry, is found to play a negligible role as a predictive measure of print uniformity in xerographic printing. Our simulation results are validated against new xerographic printing experiments of black toner onto laboratory handsheets.