Abstract: A print apparatus calibration method is disclosed. The method comprises printing, from each of a plurality of dies of a print head onto a printable substrate, an image in a first color according to a calibration pattern and an image in a second color according to the calibration pattern, the calibration pattern comprising a plurality of patches having a plurality of different densities. The method may comprise scanning, using a scanning unit, the images formed on the printable substrate to generate scanned image data, wherein the images in the first color are scanned by a first scanning module of the scanning unit and the images in the second color are scanned by a second scanning module of the scanning unit. The method may comprise analyzing, using processing apparatus, the scanned image data to identify any differences between printed densities of corresponding patches in different images of the same color. The method may comprise performing a calibration based on the analysis.

Abstract: Examples described herein relate to printhead alignment in a printing system which may print onto media of different rigidity. An example method comprises determining a flatness profile for a first type of print medium on a platen of a printing apparatus. Using the flatness profile of the first type of print medium, first alignment compensation values are determined for a printhead to print onto the first type of print medium on the platen. The flatness profile for the first type of print medium is then also used to determine second alignment compensation values for the printhead to print onto a second type of print medium on the platen, the second type of print medium being more rigid that the first type of print medium.

Abstract: In an example a method comprises operating, by a processor, on a first quantity that is proportional to a side of a parallelogram printed, at least in part, on a substrate by a fluidic die, the side of the parallelogram being substantially perpendicular to the direction of advancement of the substrate. The method further comprises operating, by a processor, on a second quantity and a third quantity, the second and third quantities respectively being proportional to the length of the lines bisecting the parallelogram. The method comprises calculating, by a processor, an angle that the fluidic die makes with the direction of advancement of the substrate based on the first, second, and third quantities.

Abstract: Examples relate to methods of calibrating a printing device. A method comprises generating a calibration sheet of a calibrating medium having a length at least equal to the maximum printing width of a printbar of the printing device and printing a plurality of calibration patterns on the calibration sheet with the printing device to be calibrated.

Abstract: A print apparatus calibration method is disclosed. The method comprises printing, from each of a plurality of dies of a print head onto a printable substrate, an image in a first color according to a calibration pattern and an image in a second color according to the calibration pattern, the calibration pattern comprising a plurality of patches having a plurality of different densities. The method may comprise scanning, using a scanning unit, the images formed on the printable substrate to generate scanned image data, wherein the images in the first color are scanned by a first scanning module of the scanning unit and the images in the second color are scanned by a second scanning module of the scanning unit. The method may comprise analyzing, using processing apparatus, the scanned image data to identify any differences between printed densities of corresponding patches in different images of the same color. The method may comprise performing a calibration based on the analysis.

Abstract: Aspects of the disclosure provide for a method. In some examples, the method includes printing a target plot comprising a color ramp, scanning the target plot via a first image scanner to determine first scan results indicating a relationship between a scanned measurement determined by the first image scanner and lightness of a scanned portion of the target plot, scanning the target plot via a second image scanner to determine second scan results indicating a relationship between a scanned measurement determined by the second image scanner and lightness of the scanned portion of the target plot, and determining a lookup table indicating a difference determined based on the first scan results and the second scan results.

Abstract: Examples relate to methods of calibrating a printing device. A method comprises generating a calibration sheet of a calibrating medium having a length at least equal to the maximum printing width of a printbar of the printing device and printing a plurality of calibration patterns on the calibration sheet with the printing device to be calibrated.