Abstract: An electrostatic aperture printer employing a gating mask placed between a source of ions and a charge receiving member to generate imagery consisting of aggregations of elemental dots or line segments formed in response to electronic control signals wherein the improvement lies in electrically biasing the mask or mask segments in such a way that the functions of ion collection and control are combined in the region between the mask and a charge receptor backing electrode via the establishment of appropriate transmission or blocking fields. Further electrostatic printing improvements incorporated are the development of useful charge receptor holddown forces via static or rolling backing electrode structures designed to make constructive use of the longitudinal tension normally developed in receptor web handling, and enhanced ion transmission achieved by means of shaped aplanar mask structures incorporating zones fabricated from insulating material.