Provided is a volume element printing system for printing a three-dimensional object. The system includes a first printhead group having a plurality of first printheads configured to print a first voxel layer on a substrate, and at least one second printhead group having a plurality of second printheads downstream from the first group. The second printhead group is configured to print a subsequent voxel layer on at least part of the first layer, said second printheads being reconfigurable as backup printheads for the first printheads in case of failure. The system also includes an object insertion device configured to insert an object into a cavity defined by the voxel layers, and a conveyor configured to convey the substrate past the printhead groups. Also included is a control system configured to control and monitor the printhead groups, the object insertion device and the conveyor, and dynamically to reconfigure the second printheads if failure of a first printhead is detected.