Organic electrophotographic receptors have been enabled by the development of unique classes of high dielectric strength glassy polymer coatings, which, though insulating, are nevertheless capable of transporting injected charge with relatively high mobility and negligible loss to deep traps. Key features of electronic transport in these materials and the underlying physics are described. Additionally, it is demonstrated that these trap-free transport polymers provide a unique venue for the exploration of contact behavior and the factors controlling injection efficiency In disordered organic solids.