Methods and apparatus for material handling in an order fulfillment center. An order fulfillment system may include a pre-shipment package preparation module that receives packaged units, and performs various post-packaging operations to facilitate shipment. Some embodiments may include an alignment section configured to orient received packaged units, a package verification section configured to verify one or more physical parameters of the packaged units, a labeling section configured to automatically apply shipping labels to each packaged unit while the packaged units travel at a constant velocity from the packaging verification section and through the labeling section, thereby applying labeling without need to stop or slow travel of the packaged units through the system. Some embodiments include a routing section that is configured to route each packaged unit to a corresponding shipping path that is selected based on information (e.g., packaged height, customer order information) associated with the given packaged unit.