Abstract: In one example of the disclosure, a first print engine is caused to print a first image in a first set of sectors of a substrate. A second print engine is caused to print a second image in a second set of sectors of the substrate. The second print engine is caused to print a cover-up image over an incidence of the first image printed by the first print engine. The second print engine is caused to print a calibration image upon the cover-up image.

Abstract: In one example in accordance with the present disclosure, a printing system is described. The printing system includes multiple print engines to form printed marks on a substrate. Each print engine prints non-sequential pages of a print job. A sensor of the printing system detects, for each page, a trailing edge gap size and a leading edge gap size. A controller of the printing system, based on a difference between trailing edge gap sizes and leading edge gap sizes for a set of pages of a print job, adjusts a printing operation to equalize subsequent trailing edge gap sizes and leading edge gap sizes.

Abstract: In one example of the disclosure, a first print engine is caused to print a first image in a first set of sectors of a substrate. A second print engine is caused to print a second image in a second set of sectors of the substrate. The second print engine is caused to print a cover-up image over an incidence of the first image printed by the first print engine. The second print engine is caused to print a calibration image upon the cover-up image.

Abstract: In one example of the disclosure, a first print engine is to print a first image in a first area of a web substrate, and is to leave blank a second area of the web substrate. The printed first image includes a set of fiducials 1-n. For each of fiducials 1-n, a fiducial position error is determined based upon a comparison of the detected position and a predicted position for a subject fiducial. A substrate advancement error is calculated based upon an average of the determined fiducial position errors. An insertion point is determined based upon the substrate advancement error. The insertion point is a point at which a second print engine in-line with the first print engine is to begin printing a second image in the second area.

Abstract: In one example in accordance with the present disclosure, a printing system is described. The printing system includes multiple print engines to form printed marks on a substrate. Each print engine prints non-sequential pages of a print job. A sensor of the printing system detects, for each page, a trailing edge gap size and a leading edge gap size. A controller of the printing system, based on a difference between trailing edge gap sizes and leading edge gap sizes for a set of pages of a print job, adjusts a printing operation to equalize subsequent trailing edge gap sizes and leading edge gap sizes.

Abstract: In one example in accordance with the present disclosure, a printing system is described. The printing system includes multiple print engines to form printed marks on a substrate. Each print engine prints non-sequential pages of a print job. A sensor of the printing system detects, for each page, a trailing edge gap size and a leading edge gap size. A controller of the printing system, based on a difference between trailing edge gap sizes and leading edge gap sizes for a set of pages of a print job, adjusts a printing operation to equalize subsequent trailing edge gap sizes and leading edge gap sizes.

Abstract: In one example of the disclosure, a first print engine is to print a first image in a first area of a web substrate, and is to leave blank a second area of the web substrate. The printed first image includes a set of fiducials 1-n. For each of fiducials 1-n, a fiducial position error is determined based upon a comparison of the detected position and a predicted position for a subject fiducial. A substrate advancement error is calculated based upon an average of the determined fiducial position errors. An insertion point is determined based upon the substrate advancement error. The insertion point is a point at which a second print engine in-line with the first print engine is to begin printing a second image in the second area.

Abstract: In one example in accordance with the present disclosure, a printing system is described. The printing system includes multiple print engines to form printed marks on a substrate. Each print engine prints non-sequential pages of a print job. A sensor of the printing system detects, for each page, a trailing edge gap size and a leading edge gap size. A controller of the printing system, based on a difference between trailing edge gap sizes and leading edge gap sizes for a set of pages of a print job, adjusts a printing operation to equalize subsequent trailing edge gap sizes and leading edge gap sizes.

Abstract: In one example of the disclosure, a first print engine is to print a first image in a first area of a web substrate, and is to leave blank a second area of the web substrate. The printed first image includes a set of fiducials 1-n. For each of fiducials 1-n, a fiducial position error is determined based upon a comparison of the detected position and a predicted position for a subject fiducial. A substrate advancement error is calculated based upon an average of the determined fiducial position errors. An insertion point is determined based upon the substrate advancement error. The insertion point is a point at which a second print engine in-line with the first print engine is to begin printing a second image in the second area.