In resistive ribbon thermal transfer printing, a printhead consisting of an array of electrodes passes current into a thin ribbon to generate heat for transferring ink to paper. The ribbon is made of a polymeric material containing carbon black so as to be conducting, and has aluminum deposited on one side of the ribbon for a base contact. In this paper, the electrical conduction processes within the ribbon are discussed. Current-voltage measurements have been made with electrodes of various types in order to separate effects due to contact resistance, aluminum/resistive ribbon interfacial resistance, and bulk conduction in the resistive ribbon. Measurements have been made over a range of frequency and temperature to determine the basic conduction mechanisms. A model of conduction is presented that is in qualitative agreement with the data.