An image formation system includes an image forming apparatus and an inserter. The image forming apparatus includes an image forming device, a conveyance device, and a control device. The control device functions as a controller and an executor. The controller allows the inserter to insert an interleaving paper between sheets of printed material at an insertion start timing specified by a print job. When the plurality of calibrations include a second calibration capable of being completed within an interleaving paper insertion time required to insert the interleaving paper or a third calibration capable of being completed within a total time of the interleaving paper insertion time and a predetermined additional time, the executor executes the second calibration or the third calibration in time with the insertion start timing.