Abstract: A printing apparatus comprises a printhead and a controller. The printhead includes dies, each die comprising rows of nozzles, wherein, in an overlapping region, the rows of nozzles of two dies overlap in a first direction, in which a relative movement between the printhead and a print medium takes place during operation of the printing apparatus. The controller is to apply a first weaving mask to a first row of nozzles of a first die and a second weaving mask to a second row of nozzles of the first die, the second weaving mask being different from the first weaving mask, the weaving masks defining, independent of print data, which of the nozzles of the corresponding row are to be used for printing in the overlapping region.

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: A printer for printing on a print medium as said print medium advances through a print zone, the printer including a number of print heads extending over the print zone, each print head including at least one nozzle array wherein at least two adjacent nozzle arrays overlap forming at least one stitching zone in the overlap region; and a printer controller for generating a sequence of nozzle firing commands for each nozzle array to selectively deposit droplets of print fluid on said print medium from said nozzle arrays in accordance with an image to be printed, wherein the printer controller further applies masks having decorrelated patterns to said sequence of firing commands for at least those overlapping nozzles of the nozzle arrays coinciding with the at least one stitching zone to obtain a predetermined optical parameter of the printed image in the stitching zone, irrespective of an offset between two adjacent nozzle arrays.

Abstract: A method in a page-wide array printing apparatus comprising at least first and second printing dies that overlap in a page width direction comprises the steps of calibrating the printing apparatus in a media advance direction to a higher resolution than the page width direction, the media advance direction being perpendicular to the page width direction, and using printing masks to control the operation of a plurality of nozzles in an overlap area between the first and second printing dies to reduce any visible defects caused by dot placement errors in the page width direction.

Abstract: In an example, a processor comprises an ancillary print agent distribution module to determine instructions for a print control module. The print control module may be to control the distribution of print agent onto a first region of a layer of build material in an object fabrication chamber in an additive manufacturing process in which at least one object is generated by selective solidification of each of a plurality of layers of build material and the selective solidification of build material is determined by the distribution of at least one print agent. The instructions determined by the ancillary print agent distribution module may be to cause the print control module to control the distribution of print agent in a second region of a layer of build material in an object fabrication chamber as part of a process which is ancillary to object generation. The first and second regions may be spatially distinct.

Abstract: A method of controlling a printer to print a pattern using a number of print head dies, each print head die including a number of nozzle trenches wherein each one of the number of nozzle trenches is associated with a different color, wherein the nozzles of neighboring dies overlap in respective overlap zones, the method comprising applying masks to the nozzles of neighboring dies in the respective overlap zones to distribute, in the overlap zones, the pattern to be printed between the nozzles of the respective neighboring dies, wherein the masks, in the overlap zones, retain the order in which the nozzles of selected nozzle trenches associated with a selected one of the colors are fired.

Abstract: Example implementations relate to swath height error compensation. Some examples may determine a density of an image to be printed in an overlap area of a printing material. The overlap area may include target pixels capable of being printed by a first set of drop ejection elements and a second set of drop ejection elements that are redundant to the first set of drop ejection elements. Some implementations may also determine a mask to apply to the first and second set of drop ejection elements based on the determined density, and the mask may designate at least one additional drop to apply to at least one target pixel in the overlap area by at least one of the first and second set of drop ejection elements. Some implementations may also apply the mask to the first set of drop ejection elements and the second set of drop ejection elements.

Abstract: A method of controlling a printer to print a pattern using a number of print head dies, each print head die including a number of nozzle trenches wherein each one of the number of nozzle trenches is associated with a different color, wherein the nozzles of neighboring dies overlap in respective overlap zones, the method comprising applying masks to the nozzles of neighboring dies in the respective overlap zones to distribute, in the overlap zones, the pattern to be printed between the nozzles of the respective neighboring dies, wherein the masks, in the overlap zones, retain the order in which the nozzles of selected nozzle trenches associated with a selected one of the colors are fired.

Abstract: Example implementations relate to swath height error compensation. Some examples may determine a density of an image to be printed in an overlap area of a printing material. The overlap area may include target pixels capable of being printed by a first set of drop ejection elements and a second set of drop ejection elements that are redundant to the first set of drop ejection elements. Some implementations may also determine a mask to apply to the first and second set of drop ejection elements based on the determined density, and the mask may designate at least one additional drop to apply to at least one target pixel in the overlap area by at least one of the first and second set of drop ejection elements. Some implementations may also apply the mask to the first set of drop ejection elements and the second set of drop ejection elements.

Abstract: A printer for printing on a print medium as said print medium advances through a print zone, the printer including a number of print heads extending over the print zone, each print head including at least one nozzle array wherein at least two adjacent nozzle arrays overlap forming at least one stitching zone in the overlap region; and a printer controller for generating a sequence of nozzle firing commands for each nozzle array to selectively deposit droplets of print fluid on said print medium from said nozzle arrays in accordance with an image to be printed, wherein the printer controller further applies masks having decorrelated patterns to said sequence of firing commands for at least those overlapping nozzles of the nozzle arrays coinciding with the at least one stitching zone to obtain a predetermined optical parameter of the printed image in the stitching zone, irrespective of an offset between two adjacent nozzle arrays.

Abstract: Example implementations relate to swath height error compensation. Some examples may determine a density of an image to be printed in an overlap area of a printing material. The overlap area may include target pixels capable of being printed by a first set of drop ejection elements and a second set of drop ejection elements that are redundant to the first set of drop ejection elements. Some implementations may also determine a mask to apply to the first and second set of drop ejection elements based on the determined density, and the mask may designate at least one additional drop to apply to at least one target pixel in the overlap area by at least one of the first and second set of drop ejection elements. Some implementations may also apply the mask to the first set of drop ejection elements and the second set of drop ejection elements.

Abstract: Example implementations relate to swath height error compensation. Some examples may determine a density of an image to be printed in an overlap area of a printing material. The overlap area may include target pixels capable of being printed by a first set of drop ejection elements and a second set of drop ejection elements that are redundant to the first set of drop ejection elements. Some implementations may also determine a mask to apply to the first and second set of drop ejection elements based on the determined density, and the mask may designate at least one additional drop to apply to at least one target pixel in the overlap area by at least one of the first and second set of drop ejection elements. Some implementations may also apply the mask to the first set of drop ejection elements and the second set of drop ejection elements.

Abstract: A method in a page-wide array printing apparatus comprising at least first and second printing dies that overlap in a page width direction comprises the steps of calibrating the printing apparatus in a media advance direction to a higher resolution than the page width direction, the media advance direction being perpendicular to the page width direction, and using printing masks to control the operation of a plurality of nozzles in an overlap area between the first and second printing dies to reduce any visible defects caused by dot placement errors in the page width direction.