Abstract: A method of forming the body portion of a three-dimensional object from a polymerizable liquid by the process of continuous liquid interface printing is described. The process includes advancing a carrier for the object away from a build surface while irradiating a build region between the carrier and build surface in a pattern of advancing and irradiating defined by an operating mode, with the body portion having a plurality of contiguous segments and with the irradiating carried out in sequentially presented slices of exposure, each having a pattern that corresponds to a segment of the body portion. Each segment has a thickness (e.g., in Z or vertical dimension) during the forming thereof. In the present invention, slice thickness is changed among the slices at least once during the formation of the body portion.