Abstract— Zenithal bistable devices (ZBD™) exhibit rugged image storage, excellent optical performance, fast latching, and infinite multiplexibility. The excellent performance characteristics are achieved using a surface‐relief grating to align the nernatic liquid crystal. Such gratings offer a high degree of design flexibility, at manufacturing costs equivalent to today's STN displays. In the present work, the grating shape is varied within each pixel to produce several separate latching thresholds, thereby introducing error‐free analog gray scales. Passive‐matrix waveforms, suitable for use with commercial STN drivers, are reported and shown to discriminate between at least seven error‐free grays in a test cell. The combination of analog and digital grays was considered. Careful selection of the digital dither weighting factors allows for a large total number of grays to be achieved, while reducing the effect of errors if all of the analog levels are not achieved.