Abstract: A method of forming a three-dimensional object includes non-deterministically generating halftone data for portions of a slice of three-dimensional model data of the three-dimensional object that overlap with a previous slice. The non-deterministically generating halftone data may comprise using randomized initialization for each slice of a three-dimensional object.

Abstract: In a 3D printing method example, color is added to a part. A build material is applied, and is pre-heated to a temperature ranging from about 50 C to about 400 C. A black ink, including an infrared absorbing colorant, is selectively applied on at least a portion of the build material. A white ink, including a white colorant that is opaque in visible wavelengths and is transparent to infrared wavelengths, is selectively applied on the black ink. A colored ink, including a colorant having a color other than black or white, is selectively applied on the white ink. The build material and the applied inks are then exposed to infrared radiation. The black ink at least partially fuses the portion of the build material in contact therewith. At least some of the white colorant and the colorant are embedded in the at least partially fused portion at a surface thereof.

Abstract: An agent distributor may be to selectively deliver agent at a first contone density and at a second contone density different from the first contone density respectively onto an interior portion and a surface portion of successive layers of build material in respective first and second patterns in accordance with data representing a three-dimensional object to be generated, so that the build material is to solidify to form slices of the three-dimensional object in accordance with the first and second patterns, and so that the three-dimensional object is to achieve a target surface roughness as a result of the second contone density of the second pattern.

Abstract: In a 3D printing method example, color is added to a part. A build material is applied, and is pre-heated to a temperature ranging from about 50 C to about 400 C. A black ink, including an infrared absorbing colorant, is selectively applied on at least a portion of the build material. A white ink, including a white colorant that is opaque in visible wavelengths and is transparent to infrared wavelengths, is selectively applied on the black ink. A colored ink, including a colorant having a color other than black or white, is selectively applied on the white ink. The build material and the applied inks are then exposed to infrared radiation. The black ink at least partially fuses the portion of the build material in contact therewith. At least some of the white colorant and the colorant are embedded in the at least partially fused portion at a surface thereof.

Abstract: In an example, an apparatus for generating a three-dimensional object includes a build area platform, a build material distributor, a secondary material ejection device, a coalescing agent ejection device, and a controller. The controller may control the secondary material ejection device to eject a secondary material in a predefined pattern over the build area platform, control the build material distributor to distribute a layer of the build material around the ejected secondary material, control the coalescing agent ejection device to eject the coalescing agent onto the layer of the build material, and control an energy source to apply energy onto the ejected coalescing agent to cause the build material in contact with the ejected coalescing agent to coalesce and solidify.

Abstract: A method of forming a three-dimensional object includes non-deterministically generating halftone data for portions of a slice of three-dimensional model data of the three-dimensional object that overlap with a previous slice. The non-deterministically generating halftone data may comprise using randomized initialization for each slice of a three-dimensional object.

Abstract: A coater comprising a transfer roller and an anilox roller, in which the coater may selectively change the direction of rotation of the transfer roller while the anilox roller maintains a singe direction of rotation.