Abstract: A print agent vessel is disclosed that comprises a circuit, the circuit comprising a first electrically conductive portion to couple to a first terminal of a printing device, a second electrically conductive portion to couple to a second terminal of the printing device, and an electrically conductive component capacitively coupled to the first electrically conductive portion. The circuit has a variable capacitance that is indicative of a parameter of the component.

Abstract: A print agent vessel is disclosed that comprises a circuit, the circuit comprising a first electrically conductive portion to couple to a first terminal of a printing device, a second electrically conductive portion to couple to a second terminal of the printing device, and an electrically conductive component capacitively coupled to the first electrically conductive portion. The circuit has a variable capacitance that is indicative of a parameter of the component.

Abstract: A replaceable print component is disclosed that comprises first and second electrodes, and a circuit electrically connected between the first and second electrodes to vary an electrical property of the circuit with a frequency component within a selected frequency range to indicate a parameter of a part of the circuit in response to a stimulus.

Abstract: A calibration apparatus is disclosed herein. An example includes a printing mechanism, a media control mechanism, a sensor, and a processor. The processor controls the printing mechanism to print a first pattern of first elements on a print medium and a second pattern of second elements on the print medium that are interleaved with the first elements. The processor also actuates the media control mechanism to advance the print medium, determines a centroid of at least one of the first elements based on a first measured reflectance by the sensor, and determines a centroid of at least one of the second elements based on a second measured reflectance by the sensor. The processor also determines a print medium advance error based on the at least one determined centroid of the first elements and the at least one determined centroid of the interleaved second elements.

Abstract: A calibration apparatus is disclosed herein. An example includes a printing mechanism, a media control mechanism, a sensor, and a processor. The processor controls the printing mechanism to print a first pattern of first elements on a print medium and a second pattern of second elements on the print medium that are interleaved with the first elements. The processor also actuates the media control mechanism to advance the print medium, determines a centroid of at least one of the first elements based on a first measured reflectance by the sensor, and determines a centroid of at least one of the second elements based on a second measured reflectance by the sensor. The processor also determines a print medium advance error based on the at least one determined centroid of the first elements and the at least one determined centroid of the interleaved second elements.

Abstract: A method of printing includes ejecting ink drops onto a bottom portion of a print media from ink orifices of a first portion of a printhead; after ejecting ink drops from the first portion of the printhead, advancing the print media; and after advancing the print media, ejecting ink drops onto the bottom portion of the print media from ink orifices of a second portion of the printhead. The second portion of the printhead is smaller than the first portion of the printhead and excludes ink orifices toward an end of the printhead opposite a direction of the advancing of the print media.

Abstract: A method of printing includes ejecting ink drops onto a bottom portion of a print media from ink orifices of a first portion of a printhead; after ejecting ink drops from the first portion of the printhead, advancing the print media; and after advancing the print media, ejecting ink drops onto the bottom portion of the print media from ink orifices of a second portion of the printhead. The second portion of the printhead is smaller than the first portion of the printhead and excludes ink orifices toward an end of the printhead opposite a direction of the advancing of the print media.