Abstract: According to one aspect, there is provided a method of detecting printhead issues in a printer. The method comprises obtaining an image to be printed, generating a first sub-pattern and a second sub-pattern, wherein the first sub-pattern in a pattern to be printed in a first pass comprising a pattern suitable to enable the detection of a printhead issue and wherein the second sub-pattern is the complementary pattern that completes the first sub-pattern such that printing the first and second sub-patterns is equivalent to printing the obtained image, printing the first sub-pattern on a print target, obtaining an image of the printed first sub-pattern, analysing the image of the printed first sub-pattern to determine the presence of a printhead issue and, where appropriate, performing a printhead maintenance operation, and printing the second sub-pattern on the print target.

Abstract: According to one example, there is provided an apparatus to process volume of particulate build material. The apparatus comprises a sealable chamber to house a volume of particulate build material, a gas supply to supply the chamber with a predetermined gas, a gas circulator to circulate the gas within the volume of build material, a temperature controller to heat the circulated gas to a predetermined heating temperature to heat the volume of build material to the heating temperature and then to cool the circulated gas to a predetermined cooling temperature to cool the volume of build material to the cooling temperature.

Abstract: In an example, a data unit includes a mounting to removably mount the data unit on a receiving portion of an additive manufacturing build material container, a data source to provide data comprising a plurality of additive manufacturing parameters and a communications interface to communicate with a reader of an additive manufacturing build material processing apparatus. The communications interface is to transmit data from the data source to the additive manufacturing build material processing apparatus.

Abstract: A printer is described that comprises a print chamber and an electromagnet moveable within the print chamber. The electromagnet has an on state and an off state. The electromagnet is to collect magnetic powder within the print chamber when in the on state, and to deposit magnetic powder when in the off state.

Abstract: A method for reducing artefacts in printed objects comprises receiving print data to be printed by a printhead arrangement, the printhead arrangement being movable in a print direction and comprising a plurality of printhead dies, wherein printhead dies adjacent to each other comprise an overlap area when viewed in the print direction. The print data to be printed are modified near and/or at the overlap areas between printhead dies of the printhead arrangement to compensate for drop placement.

Abstract: There is disclosed a non-transitory machine readable storage medium encoded with instructions executable by a processor and comprising instructions to: receive object data corresponding to a three-dimensional object to be generated; define print data for each of a plurality of slices of the object to control a respective layer forming operation in which print agent is ejected on a layer of build material in a pattern corresponding to selective fusing of the build material, wherein the print data and the respective pattern is defined for each slice according to object a print definition procedure; and select the print definition procedure from a plurality of print definition procedures based on a user input. There is also disclosed a corresponding method and additive manufacturing apparatus.

Abstract: In an example, an additive manufacturing device comprises a sensor, a moveable radiation source and a controller. The controller may determine an output of the sensor at a point at which build material melts by causing the moveable radiation source to periodically move over a layer of the build material to provide radiation to the layer of build material and monitoring the output of the sensor.

Abstract: In an example, a data unit includes a data unit mounting having a circuitry region, a registration portion, and a retaining feature. Circuitry comprising a data source to provide at least one additive manufacturing parameter is arranged on the circuitry region of the mounting. The data unit mounting is to be removably mounted on a receiving portion of an additive manufacturing build material component, such that the registration portion is to be received in a corresponding guide portion of the receiving portion of the additive manufacturing build material component, and the retaining feature is prevent removal of the data unit from the receiving portion unless deformed. Deformation of the retaining feature to effect removal of the data unit from the receiving portion may be a permanent deformation.

Abstract: Certain examples described herein control an amount of a functional agent that is deposited in a three-dimensional printing system. In certain examples, an amount of a functional agent is controlled based on a distance function, wherein the distance function is associated with a distance between a particular portion of an object to be fabricated and a surface of the object. The functional agent may be a binder, a fusing agent or a detailing agent, amongst others.

Abstract: An example device includes a camera to aim towards a build platform to receive material to be fused to form an article. The camera is to capture thermal images including a correction image captured during formation of the article at the build platform. The correction image is to be referenced to adjust a parameter of the formation of the article at the build platform. The example device further includes a controller connected to the camera. The controller is to control the camera to capture a calibration image with a heater associated with the build platform turned on. The controller is further to use the calibration image to compute a calibration to apply to the correction image.

Abstract: A three-dimensional object is generated using a build material and a printing agent. A visible property of one of the build material and the printing agent is identified. The other of the build material and the printing agent is selected based at least on the other of the build material and the printing agent having a given visible property. A three-dimensional object is generated using the one of build material and the printing agent having the identified visible property and the other of the build material and the printing agent having the given visible property. The selecting is based at least on the identified visible property and the given visible property having a desired visible property relationship. An apparatus for building a three-dimensional object is also disclosed.

Abstract: In an example an additive manufacturing system for generating a three-dimensional object by processing successive layers of build material comprises a controller to: receive data relating to a three-dimensional object to be generated; calculate, based at least in part on the data relating to the three-dimensional object, an estimated time to process each layer of build material; determine the longest time of said estimated times; and configure the additive manufacturing system to process each layer of build material in a time which is the same, within a predetermined tolerance, for all of the layers, and which is at least as long as the determined longest time.

Abstract: In an example, a data unit includes a mounting to removably mount the data unit on a receiving portion of an additive manufacturing build material container, a data source to provide data comprising a plurality of additive manufacturing parameters and a communications interface to communicate with a reader of an additive manufacturing build material processing apparatus. The communications interface is to transmit data from the data source to the additive manufacturing build material processing apparatus.

Abstract: In an example, a data unit includes a mounting to removably mount the data unit on a receiving portion of an additive manufacturing build material container, a data source to provide data comprising a plurality of additive manufacturing parameters and a communications interface to communicate with a reader of an additive manufacturing build material processing apparatus. The communications interface is to transmit data from the data source to the additive manufacturing build material processing apparatus.

Abstract: In an example, a method includes monitoring a temperature of a layer of build material within an additive manufacturing apparatus. A power level of a first heating element heating the layer of build material may be controlled based on the monitored temperature and a power level of a second heating element heating the layer of build material may be controlled according to a predetermined power level scheme.

Abstract: Methods of generating a three-dimensional object with an additive manufacturing system are described. The method includes depositing a build material within a working area, thereby providing a build material layer, selectively depositing a fusing agent onto a portion of the build material layer, applying energy from a bulk-fusion energy source to the working area, thereby fusing at least a portion of the build material where the fusing agent is deposited, and applying energy from a focused energy source to one or more localized areas of the working area.

Abstract: As one example, a printer includes a density calculator to determine a content density of data on page to be printed and a controller. In that example, the controller may perform operations to determine a dry time for a swath of the page to be printed based on the content density and an environmental variable and adjust a parameter for the page to be printed to mitigate a drying time of the page to be printed based on the dry time determined for the swath.

Abstract: The present disclosure is drawn to fabric print media and a method of coating a fabric substrate to form a fabric print medium. The fabric print medium can comprise a primer layer applied to the fabric substrate, an ink-fixing layer applied to the primer layer, and an ink-receiving layer applied to the ink-fixing layer. The primer layer can include a first film-forming polymer and a fabric softening agent. The ink-fixing layer can comprise a second film-forming polymer and a cationic compound. The ink-receiving layer can comprise a third film-forming polymer and non-deformable particles. One or more of the primer layer, the ink-fixing layer, and the ink-receiving layer also further comprise a flame inhibitor. In one example, all of these three layers include the flame inhibitor.

Abstract: According to one example, there is provided a printing system. The printing system comprises a support having a plurality of spaced apertures and a colour sensor moveable to measure light from each aperture. The printing system further comprises a controller to control the colour sensor to measure characteristics of light emitted through each aperture, and to determine, for each aperture, light calibration data.

Abstract: Implementations disclose a method and system for providing a self-adaptive image. According to one implementation, a first non-white ink layer on is deposited on a substrate. Furthermore, a white ink layer is deposited over the first non-white ink layer and below a second non-white ink layer deposited thereon.