Abstract: A three-dimensional object may be generated. First and second agent distributors may be to respectively selectively deliver a binder agent and a coalescing agent onto portions of a layer of build material. A controller may be to control the first and second agent distributors to respectively selectively deliver the binder agent and the coalescing agent onto respective first and second portions of the layer in patterns derived from data representing a slice of the three-dimensional object to be generated. The first portion having the binder agent may be to bind and solidify into a binder matrix. When energy is applied to the layer the second portion having the second agent may be to coalesce and solidify.

Abstract: A coalescing agent for three-dimensional (3D) printing includes a co-solvent, a surfactant having a hydrophilic lipophilic balance (HLB) value that is less than 10, a carbon black pigment, a polymeric dispersant, and a balance of water. The co-solvent is present in an amount ranging from about 15 wt % to about 30 wt % of a total wt % of the coalescing agent. The surfactant is present in an amount ranging from about 0.5 wt % to about 1.4 wt % of the total wt % of the coalescing agent. The carbon black pigment is present in an amount ranging from about 3.0 wt % to about 6.0 wt % of the total wt % of the coalescing agent. The polymeric dispersant has a weight average molecular weight ranging from about 12,000 to about 20,000.

Abstract: A coalescing agent for three-dimensional (3D) printing includes a co-solvent, a surfactant having a hydrophilic lipophilic balance (HLB) value that is less than 10, a carbon black pigment, a polymeric dispersant, and a balance of water. The cosolvent is present in an amount ranging from about 15 wt % to about 30 wt % of a total wt % of the coalescing agent. The surfactant is present in an amount ranging from about 0.5 wt % to about 1.4 wt % of the total wt % of the coalescing agent. The carbon black pigment is present in an amount ranging from about 3.0 wt % to about 6.0 wt % of the total wt % of the coalescing agent. The polymeric dispersant has a weight average molecular weight ranging from about 12,000 to about 20,000.

Abstract: A three-dimensional (3D) printing method includes applying a build material, including: a plurality of first reactive particles; a plurality of second reactive particles, the first and second reactive particles to react with each other upon contact there with; and a coating on i) the plurality of first reactive particles; or ii) the plurality of second reactive particles; or iii) both i) and ii). The coating is to isolate the plurality of first reactive from the plurality of second reactive particles. A fluid is selectively applied on a portion of the build material, the fluid disrupting the coating on the portion of the build material to render the first and second reactive particles in the portion of the build material in contact with each other. The contact initiates mutual reacting and fusing between the first and second reactive particles.

Abstract: In a computational modeling method for identifying how to apply a modifying agent during a three-dimensional (3D) printing method, a thermal diffusion model of a layer of a 3D object to be formed from a portion of a sinterable material using the 3D printing method is created. The thermal diffusion model is created by a computer running computer readable instructions stored on a non-transitory, tangible computer readable storage medium. A quantity of the modifying agent to be selectively applied is calculated, by the computer, based upon the thermal diffusion model.

Abstract: A detailing agent for three-dimensional (3D) printing includes a colorant present in an amount ranging from about 1.00 wt % to about 3.00 wt % based on a total weight of the detailing agent. The colorant is a dye having substantially no absorbance in a range of 650 nm to 2500 nm. The detailing agent also includes a co-solvent, a surfactant, and a balance of water.

Abstract: Provided in one example herein is a three-dimensional printing method, comprising: (A) forming a layer comprising particles comprising a polymer and cavities between the particles, wherein the particles have an average diameter of between about 5 ?m and about 250 ?m; (B) disposing a liquid suspension over at least a portion of the layer such that the liquid suspension infiltrates into the cavities, wherein the liquid suspension comprises a radiation-absorbing coalescent agent and nanoparticles having an average diameter of less than or equal to about 500 nm; (C) forming an object slice by exposing the infiltrated layer to a radiant energy, wherein the object slice comprises a polymeric matrix comprising the polymeric particles, at least some of which are fused to one another, and the nanoparticles within the polymeric matrix; and (D) repeating (A) to (C) to form the three-dimensional object comprising multiple object slices bound depth-wise to one another.

Abstract: The present disclosure is drawn to material sets for 3-dimensional printing. The material set can include a thermoplastic polymer powder having an average particle size from 20 ?m to 200 ?m, a conductive fusing agent composition including a transition metal, and nonconductive fusing agent composition. The nonconductive fusing agent composition can include transition metal oxide bronze particles.

Abstract: A three-dimensional (3D) printing system includes a fabrication bed, a build material to be introduced into the fabrication bed, an inkjet applicator, a coalescing agent to be selectively introduced by the inkjet applicator onto the build material in the fabrication bed, and a radiation source to expose the coalescing agent and the build material in the fabrication bed to electromagnetic radiation. The coalescing agent includes a co-solvent having a boiling point of less than 300 C, a surfactant having a hydrophilic lipophilic balance (HLB) value that is less than 10, a carbon black pigment, a polymeric dispersant, and a balance of water.

Abstract: An inkjet printing system is described herein. In an implementation, the inkjet printing system includes a fixer dispensing unit for applying a fixer composition on a substrate and an ink dispensing unit for applying an ink composition on the substrate. The fixer composition includes a metal salt in a range of about 5% to 10% by weight. Further, the ink composition includes a liquid vehicle having a non-volatile organic solvent, a colorant dispersed in the liquid vehicle, and a latex binder dispersed in the liquid vehicle.

Abstract: An example of a pre-treatment fixing fluid for an offset coated medium includes calcium propionate, calcium pantothenate, tetraethylene glycol, a surfactant having an HLB less than 10, an acid, and a balance of water. The calcium propionate is present in an amount ranging from greater than 4.5 wt % to 8.0 wt %, the calcium pantothenate is present in an amount ranging from about 2.0 wt % to equal to or less than 15 wt %, and the surfactant is present in an amount ranging from about 0.01 wt % to about 1.0 wt %, each based on the total wt % of the pre-treatment fixing fluid. The acid is present in an amount sufficient to render the pH from about 4.0 to about 7.0.

Abstract: The present disclosure is drawn to material sets and 3-dimensional printing systems that include a fusing agent. One example of a material set can include a detailing agent including water; a splash reducing compound comprising an infrared-absorbing dye, a polymeric binder, or combination thereof; and a water-soluble co-solvent. The material set can further include a fusing agent including water and an energy absorber.

Abstract: The present disclosure is drawn to material sets and 3-dimensional printing systems that include a fusing agent. One example of a material set can include a fusing agent and a detailing agent. The fusing agent can include water, a carbon black pigment, and a water-soluble co-solvent in an amount from 20 wt % to 60 wt %. The detailing agent can include water and a black dye. In another example, a material set can include a fusing agent and a thermoplastic polymer powder.

Abstract: The present disclosure is drawn material sets, coalescent fluids, and 3-dimensional printing systems. An example material set can include an amorphous polymer powder having an average particle size from 1 micron to 300 microns, and a coalescent fluid including a viscosity reducing agent.

Abstract: In a coating method example, a coating is formed on a part precursor by blasting the part precursor with a blast medium. The blast medium includes blasting beads and a coating agent. The part precursor is formed from a polymeric build material, and a hardness of the blasting beads is greater than a hardness of the polymeric build material.

Abstract: The present disclosure is drawn to a composite particulate build material, including 92 wt % to 99.5 wt % polymeric particles having an average size from 10 ?m to 150 ?m and an average aspect ratio of less than 2:1. The composite particulate build material further includes from 0.5 wt % to 8 wt % reinforcing particles having an average size of 0.1 ?m to 20 ?m and an average aspect ratio of 3:1 to 100:1 applied to a surface of the polymeric particles.

Abstract: A fixable, UV curable ink includes an aqueous ink vehicle including water and a co-solvent, a pigment, and a dispersant. A polyurethane polymer dispersion is suspended as droplets within the aqueous ink vehicle. The polyurethane polymer dispersion includes a polyurethane polymer selected from the group consisting of a polyether-based polyurethane, a polyester-based polyurethane, a polycarbonate-based polyurethane, and mixtures thereof. The polyurethane polymer has i) an acid number ranging from 0 mg/g to less than 20 mg/g and ii) a glass transition temperature of less than 0° C. A water soluble or water dispersible photoinitiator is present in the fixable, UV curable ink. A base may be included in an amount sufficient to adjust a pH of the UV curable ink so that it ranges from 7.5 to 9.5. An additive may be included and selected from the group consisting of a biocide, a non-ionic surfactant, an anti-kogation agent, a buffer, and combinations thereof.

Abstract: A pretreatment fluid for printing media with a pigment ink composition includes a liquid vehicle, at least one polymeric binder having pendant carboxyl groups, and an ammonium metal chelate cross-linker.

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: Examples relate to defining layers for generating three-dimensional objects. In the examples herein, a grid is obtained to represent a layer of a three-dimensional object. A boundary portion of the grid is defined, representing a surface portion of the three-dimensional object. A binding agent load is assigned to the boundary portion based on first pattern. An interior portion of the grid is defined. A coalescing agent load is assigned to the interior portion based on a second pattern.