An ink jet printing system comprising: - a print station disposed at a sheet transport path diverging to a first and a second output holder; - a sheet feeder arranged to feed a stream of media sheets into the transport path so as to be fed sequentially to the print station; - a duplex loop; - a sensor arranged at the transport path for detecting a quality condition of the sheets being fed to the print station, the sensor being arranged to scan a surface relief of a sheet that is moving past the sensor and being disposed at a point of the sheet transport path between the print station and a junction where sheets returning from the duplex loop enter into the sheet transport path again; - a sheet ejector disposed at the sheet transport path in a position between the sensor and the print station for ejecting unsuitable sheets from the transport path to a discharge path based on a comparison of the scanned surface relief of the sheets and a print gap spacing of the print station; and - a controller arranged to receive print instructions concerning a first and a second set (S1, S2) of images to be printed and to schedule a print order of images to be consecutively printed on the sheets, characterized in that: the controller is further arranged to: - schedule images of the first and second sets (S1, S2) into an alternating image sequence defining the print order, such that the print station alternatingly prints images of the first and second set (S1, S2) on the sheets in the stream; - direct sheets printed with images from the first set to the first output holder; - direct sheets printed with images from the second set to the second output holder; when at least one sheet in the second set is ejected to the discharge path: - direct printed sheets of the first set following the rejected sheet to the first output holder; - direct sheets of the second set following the rejected sheet to the discharge path. - a print station disposed at a sheet transport path diverging to a first and a second output holder; - a sheet feeder arranged to feed a stream of media sheets into the transport path so as to be fed sequentially to the print station; - a duplex loop; - a sensor arranged at the transport path for detecting a quality condition of the sheets being fed to the print station, the sensor being arranged to scan a surface relief of a sheet that is moving past the sensor and being disposed at a point of the sheet transport path between the print station and a junction where sheets returning from the duplex loop enter into the sheet transport path again; - a sheet ejector disposed at the sheet transport path in a position between the sensor and the print station for ejecting unsuitable sheets from the transport path to a discharge path based on a comparison of the scanned surface relief of the sheets and a print gap spacing of the print station; and - a controller arranged to receive print instructions concerning a first and a second set (S1, S2) of images to be printed and to schedule a print order of images to be consecutively printed on the sheets, the controller is further arranged to: - schedule images of the first and second sets (S1, S2) into an alternating image sequence defining the print order, such that the print station alternatingly prints images of the first and second set (S1, S2) on the sheets in the stream; - direct sheets printed with images from the first set to the first output holder; - direct sheets printed with images from the second set to the second output holder; - schedule images of the first and second sets (S1, S2) into an alternating image sequence defining the print order, such that the print station alternatingly prints images of the first and second set (S1, S2) on the sheets in the stream; - direct sheets printed with images from the first set to the first output holder; - direct sheets printed with images from the second set to the second output holder; when at least one sheet in the second set is ejected to the discharge path: - direct printed sheets of the first set following the rejected sheet to the first output holder; - direct sheets of the second set following the rejected sheet to the discharge path. - direct printed sheets of the first set following the rejected sheet to the first output holder; - direct sheets of the second set following the rejected sheet to the discharge path.