During gravity sedimentation of finely divided precipitates and flocculated materials liquid channels free of solids may be observed within the suspension or sediment. Some considerable time may pass before the top of the channels reaches the batch settling suspension/supernatant interface. During this time fronts of increasing solid concentration, or characteristics, propagate from the base of the batch settling column. Solid concentration measurements and observations during the sedimentation of calcite suspensions showed that the top of the channel region coincided with a solid concentration characteristic. The solid concentration of this characteristic represented the first significant increase in concentration over that of the original suspension, and not a unique characteristic value, when performing sedimentations at different starting concentrations. The region above the top of the channels diluted, and this increased the suspension/supernatant interface velocity. Further rapid acceleration occurred when the top of the channels reached the interface, prior to the consolidation period when the interface slowed and compression resulted in a maximum sediment concentration of 18% by volume. Stirring the suspension at a speed of 1 rpm completely suppressed the channels and, under these conditions, the maximum sediment concentration was 34% by volume. The sedimentation velocity and, therefore, flux at the interface was up to 26% greater in the presence of channels. However, for concentrations between 10 and 33% v/v stirring improved the batch sedimentation flux. Hence, if the flux limiting concentration during continuous thickening of this material is between 10 and 33% by volume, conditions that do not promote channels should be employed for maximum settling capacity. Increased underflow concentration would also be possible.