Abstract: In an example, replaceable print apparatus component authentication apparatus comprises a memory and circuitry. An electrical characteristic of the circuitry may be variable in response to a stimulus, and the memory may store data indicative of an expected variation in the electrical characteristic in response to the stimulus which is associated with a variation in capacitance.

Abstract: In an example, a method comprises fabricating a first validation device for association with a first replaceable print apparatus component. The device may be to form part of circuitry arranged on the first replaceable print apparatus component, and may provide an associated electrically detectable characteristic which varies with the position of at least part of the first validation device. The electrically detectable characteristic may be measured and data indicative of the characteristic may be stored in a first memory. The first replaceable print apparatus component comprising the first device and the first memory may be assembled.

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: In an example, a fluid level sensor comprises a vibrational paddle wherein an edge of the vibrational paddle comprises a fluid surface contact point having a peaked profile.

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 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: In an example, replaceable print apparatus component authentication apparatus comprises a memory and circuitry. An electrical characteristic of the circuitry may be variable in response to a stimulus, and the memory may store data indicative of an expected variation in the electrical characteristic in response to the stimulus which is associated with a variation in capacitance.

Abstract: A fluid container orientation sensor is disclosed. The fluid container orientation sensor may comprise a first vibrational member having a first resonant behaviour and a second vibrational member having a second resonant behaviour. The first vibrational member may be disposed at a first depth within the fluid container. The second vibrational member may be disposed at a second depth within the fluid container A method and a print apparatus are also disclosed.

Abstract: In an example, a method comprises fabricating a first validation device for association with a first replaceable print apparatus component. The device may be to form part of circuitry arranged on the first replaceable print apparatus component, and may provide an associated electrically detectable characteristic which varies with the position of at least part of the first validation device. The electrically detectable characteristic may be measured and data indicative of the characteristic may be stored in a first memory. The first replaceable print apparatus component comprising the first device and the first memory may be assembled.

Abstract: An ink cartridge is disclosed that includes a single cast reservoir portion of a first polymer configuration, the reservoir portion including raised walls that extend up to a top edge, the raised walls including a back wall. A latch handle protrudes from the back wall. A single cast lid is attached to the top edge. The lid is of a second polymer configuration that is stronger than the first polymer configuration.

Abstract: Liquid supply or reservoir therefore having multiple compartments, each compartment to hold a distinct liquid, comprising multiple liquid outlets, each fluidically connected to one of the compartments, multiple clearance cut outs disposed at a pitch equal to a pitch of the compartments to accommodate protrusions of a dispenser, and at least one latch protruding outwards from a supply wall.

Abstract: Liquid supply or reservoir therefore having multiple compartments, each compartment to hold a distinct liquid, comprising multiple liquid outlets, each fluidically connected to one of the compartments, multiple clearance cut outs disposed at a pitch equal to a pitch of the compartments to accommodate protrusions of a dispenser, and at least one latch protruding outwards from a supply wall.

Abstract: Liquid supply or reservoir therefore having multiple compartments, each compartment to hold a distinct liquid, comprising multiple liquid outlets, each fluidically connected to one of the compartments, multiple clearance cut outs disposed at a pitch equal to a pitch of the compartments to accommodate protrusions of a dispenser, and at least one latch protruding outwards from a supply wall.

Abstract: Liquid supply or reservoir therefore having multiple compartments, each compartment to hold a distinct liquid, comprising multiple liquid outlets, each fluidically connected to one of the compartments, multiple clearance cut outs disposed at a pitch equal to a pitch of the compartments to accommodate protrusions of a dispenser, and at least one latch protruding outwards from a supply wall.

Abstract: An ink cartridge is disclosed that includes a single cast reservoir portion of a first polymer configuration, the reservoir portion including raised walls that extend up to a top edge, the raised walls including a back wall. A latch handle protrudes from the back wall. A single cast lid is attached to the top edge. The lid is of a second polymer configuration that is stronger than the first polymer configuration.

Abstract: A developer sheet for use in pressure-sensitive carbonless paper which incorporates a hollow microspherical plastic pigment.