Abstract: Certain examples describe a method of calibrating a printer and a printing system. An interferential pattern is printed in the form of a print calibration image on a print medium. Data representative of the interferential pattern as printed on the print medium is detected using an optical sensor. The printer is calibrated based on the captured data. The interferential pattern is based on a waveform that varies in amplitude along an axis perpendicular to a printing axis under calibration and has repeated sets of multiple patterns based on the waveform, the repeated sets having a varying pattern spacing in the printing axis under calibration.

Abstract: A method of printing on a printable medium is disclosed. The method of printing may use a print head having a plurality of nozzles. The printable medium may have a leading edge and a defined zone adjacent to the leading edge. The print head may deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise printing outside, and not within, the defined zone on the printable medium using a first subset of nozzles of the plurality of nozzles. The method may further comprise printing within, and not outside, the defined zone on the printable medium using a second subset of nozzles of the plurality of nozzles.

Abstract: A method of printing is disclosed. The printing may involve printing on a printable medium using a print head having a plurality of nozzles, the printable medium having a leading edge and a defined zone adjacent to the leading edge. The print head may be to deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise: during a first printing pass, depositing print agent from a subset of the plurality of nozzles onto the printable medium outside the defined zone. The method may further comprise: advancing the printable medium by a defined distance. The method may further comprise: during a second printing pass, depositing print agent from a subset of the plurality of nozzles onto the printable medium within the defined zone.

Abstract: Misalignments of a 3d printing device may be detected by providing a reference pattern in a print zone of the 3d printing device, wherein the reference pattern comprises a plurality of reference marks, printing a test pattern on the reference pattern by means of the 3d printing device, and comparing the test pattern with the reference marks.

Abstract: A method of printing on a printable medium is disclosed. The method of printing may use a print head having a plurality of nozzles. The printable medium may have a leading edge and a defined zone adjacent to the leading edge. The print head may deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise printing outside, and not within, the defined zone on the printable medium using a first subset of nozzles of the plurality of nozzles. The method may further comprise printing within, and not outside, the defined zone on the printable medium using a second subset of nozzles of the plurality of nozzles.

Abstract: A method of printing is disclosed. The printing may involve printing on a printable medium using a print head having a plurality of nozzles, the printable medium having a leading edge and a defined zone adjacent to the leading edge. The print head may be to deposit print agent onto the printable medium via the plurality of nozzles during successive printing passes. The method may comprise: during a first printing pass, depositing print agent from a subset of the plurality of nozzles onto the printable medium outside the defined zone. The method may further comprise: advancing the printable medium by a defined distance.

Abstract: Misalignments of a 3d printing device may be detected by providing a reference pattern in a print zone of the 3d printing device, wherein the reference pattern comprises a plurality of reference marks, printing a test pattern on the reference pattern by means of the 3d printing device, and comparing the test pattern with the reference marks.

Abstract: The invention relates to a fluid ejection system comprising a print head unit including a fluid ejection nozzle array, wherein the fluid ejection nozzle array comprises at least a first set of nozzles having nozzles of a first fluid ejection capacity and a second set of nozzles having nozzles of a second fluid ejection capacity and nozzles of a third fluid ejection capacity, wherein the first fluid ejection capacity, the second fluid ejection capacity and the third fluid ejection capacity are different from one another, and further including a printer controller which, in a first printing mode, selects nozzles of the first and second sets for firing in proportions so that the overall color densities generated by the nozzles of second set when compared to nozzles of the first set are the same in a defined print area.

Abstract: An N-pass hybrid fill-and-line print mode is used to print an image on a print medium. In this mode, each sequence of N longitudinally overlapping printhead passes over said print media includes at least one transverse forward pass using a fill mask and at least one transverse reverse pass using a line mask.

Abstract: The invention relates to a fluid ejection system comprising a print head unit including a fluid ejection nozzle array, wherein the fluid ejection nozzle array comprises at least a first set of nozzles having nozzles of a first fluid ejection capacity and a second set of nozzles having nozzles of a second fluid ejection capacity and nozzles of a third fluid ejection capacity, wherein the first fluid ejection capacity, the second fluid ejection capacity and the third fluid ejection capacity are different from one another, and further including a printer controller which, in a first printing mode, selects nozzles of the first and second sets for firing in proportions so that the overall color densities generated by the nozzles of second set when compared to nozzles of the first set are the same in a defined print area.

Abstract: An N-pass hybrid fill-and-line print mode is used to print an image on a print medium. In this mode, each sequence of N longitudinally overlapping printhead passes over said print media includes at least one transverse forward pass using a fill mask and at least one transverse reverse pass using a line mask.