Abstract: The present disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed objects. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and a chemical functionalization agent. The fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation energy and convert the radiation energy to heat. The chemical functionalization agent can include water and an amine-containing polymer. The amine-containing polymer can be a branched or unbranched polymer that includes a polymer backbone and multiple pendant side chains. The individual side chains can include —NH2, —NH—, or a combination thereof.

Abstract: A three-dimensional printing kit can include a fusing agent including water and a radiation absorber and a build material that can include from 95 wt % to 100 wt % of annealed polyether polyamide copolymer particles that can have a D50 particle size from about 2 ?m to about 150 ?m.

Abstract: Three-dimensional printing kits can include a powder bed material with from about 60 wt % to about 95 wt % polymer build particles and about 5 wt % to about 40 wt % calcium carbonate particles, and a fusing agent to selectively apply to the powder bed material, wherein the fusing agent includes water and a radiation absorber to absorb radiation energy and convert the radiation energy to heat.

Abstract: This disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of testing powder bed material for contamination. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and a detector solution. The fusing agent can include water, an electromagnetic radiation absorber, and a first pigment reactant. The electromagnetic radiation absorber can absorb radiation energy and convert the radiation energy to heat. The detector solution can include water and a second pigment reactant.

Abstract: The present disclosure describes three-dimensional printing with scent agents. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent comprising water and a radiation absorber, wherein the radiation absorber absorbs radiation energy and converts the radiation energy to heat; and a scent agent comprising a scented compound dissolved in an aqueous liquid vehicle that includes water and organic co-solvent, wherein the organic co-solvent includes an aliphatic polyol, an esterified aliphatic polyol, or a combination thereof.

Abstract: This disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of sensing metal ions using three-dimensional printed ion sensors. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and an ion-sensing agent. The fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation energy and convert the radiation energy to heat. The ion-sensing agent can include water and a redox-active inorganic salt.

Abstract: A multi-fluid kit for three-dimensional printing can include a fusing agent and a detailing agent. The fusing agent can include water and a radiation absorber. The radiation absorber absorbs radiation energy and converts the radiation energy to heat. The detailing agent includes a lipophilic phase discontinuously dispersed within an aqueous phase by a surfactant. The lipophilic phase includes an organosilane having a central silicon atom coupled to a C6 to C24 aliphatic or alicyclic hydrocarbon and multiple hydrolyzable groups. The organosilane is present in the detailing agent at from about 1 wt % to about 20 wt %.

Abstract: This disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent, a first reactive agent, and a second reactive agent. The fusing agent can include water and a radiation absorber. The radiation absorber can absorb radiation energy and convert the radiation energy to heat. The first reactive agent can include water and a dissolved first pigment reactant. The second reactive agent can include water and a dissolved second pigment reactant. The second pigment reactant can be reactive with the first pigment reactant to form a water-insoluble pigment.

Abstract: A multi-fluid kit for three-dimensional printing can include a fusing agent and a coloring agent. The fusing agent can include an electromagnetic radiation absorber in a first liquid vehicle. The electromagnetic radiation absorber can absorb radiation energy and can convert the radiation energy to heat. The coloring agent can include a magenta rhodamine dye and a fluorescence quenching iodide salt in a second liquid vehicle. A molar ratio of the magenta rhodamine dye to the fluorescence quenching iodide salt can range from about 1:1 to about 1:10.

Abstract: The present disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent, a hydrophobizing agent, and a hydrophilizing agent. The fusing agent can include water and an electromagnetic radiation absorber, wherein the electromagnetic radiation absorber absorbs radiation energy and converts the radiation energy to heat. The hydrophobizing agent can include water and a hydrophobic additive including a first polymer having a hydrophobic group, a monomer that is polymerizable to form a first polymer having a hydrophobic group, or a combination thereof. The hydrophilizing agent can include water and a hydrophilic additive including a second polymer having a hydrophilic group.

Abstract: A multi-fluid kits for three-dimensional printing can include a fusing agent and a tinted anti-coalescing agent. The fusing agent can include water and an electromagnetic radiation absorber that absorbs radiation energy and converts the radiation energy to heat. The tinted anti-coalescing agent can include an aqueous liquid vehicle, a colored dye dissolved in the aqueous liquid vehicle, and a polyelectrolyte. The polyelectrolyte can have a weight average molecular weight from about 1,000 Mw to about 8,000 Mw, the polyelectrolyte can be water-absorbent at a water to polyelectrolyte weight ratio from about 2:1 to about 1,000:1, and about 90 wt % to 100 wt % of the polyelectrolyte can be dissolved in the aqueous liquid vehicle.

Abstract: Three-dimensional printing kits can include a powder bed material and a fusing agent to selectively apply to the powder bed material. The powder bed material can include polymer build particles and cellulose particles. The cellulose particles can be chemically and thermally stable at a melting point temperature of the polymer build particles. The fusing agent can include water and a radiation absorber to absorb radiation energy and convert the radiation energy to heat.

Abstract: This disclosure describes three-dimensional printing kits, methods of making three-dimensional printed objects, and systems for three-dimensional printing. In one example, a three-dimensional printing kit can include a powder bed material and a fusing agent to selectively apply to the powder bed material. The powder bed material can include polymer particles and a redox-active inorganic salt mixed with the polymer particles. The fusing agent can include water and an electromagnetic radiation absorber, wherein the electromagnetic radiation absorber absorbs electromagnetic radiation energy and converts the electromagnetic radiation energy to heat.

Abstract: This disclosure describes three-dimensional printing kits, methods, and systems for three-dimensional printing with phosphorescent pigments. In one example, a three-dimensional printing kit can include a powder bed material and a low-tint fusing agent. The powder bed material can include polymer particles and phosphorescent pigment particles mixed with the polymer particles. The low-tint fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation energy and convert the absorbed radiation energy to heat.

Abstract: The present disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed articles. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and a scent agent. The fusing agent can include water and a radiation absorber. The radiation absorber can absorb radiation energy and convert the radiation energy to heat. The scent agent can include water and a scent additive. The scent additive can be chemically stable at an elevated temperature from about 70° C. to about 350° C.

Abstract: A three-dimensional printing kit can include a powder bed material and a fusing agent to selectively apply to the powder bed material. The powder bed material can include polymer particles and a thermochromic additive. The thermochromic additive can be chemically stable at a melting point temperature of the polymer particles, and the thermochromic additive can exhibit a color change at a color transition temperature that is below the melting point of the polymer particles. The fusing agent can include water and a radiation absorber to absorb radiation energy and convert the radiation energy to heat.

Abstract: In an example of a method for three-dimensional (3D) printing, a polymeric build material is applied to form a build material layer. A fusing agent is selectively applied, based on a 3D object model, onto the build material layer to form a patterned portion. A hydrophobic agent is selectively applied, based on the 3D object model, onto at least a portion of the patterned portion. The hydrophobic agent includes a perfluorinated polymer having a mean particle size ranging from about 50 nm to about 195 nm. The build material layer is exposed to energy to selectively coalesce the patterned portion and form a 3D object layer having a hydrophobic portion.

Abstract: A three-dimensional (3D) printing kit includes a build material composition and a fusing agent. The build material composition includes biodegradable polyester particles having a volume-based particle size distribution including D10 ranging from about 65 ?m to about 85 ?m, D50 ranging from about 125 ?m to about 145 ?m, and D90 ranging from about 225 pm to about 245 ?m. The fusing agent includes an energy absorber dissolved or dispersed in a liquid vehicle.

Abstract: In an example of a method for three-dimensional (3D) printing, a polymeric build material is applied to form a build material layer. A fusing agent is selectively applied, based on a 3D object model, onto the build material layer to form a patterned portion. A hydrophobic agent is selectively applied, based on the 3D object model, onto at least a portion of the patterned portion. The hydrophobic agent includes a lipophilic phase discontinuously dispersed within an aqueous phase by a surfactant, wherein the lipophilic phase includes an organosilane having a central silicon atom coupled to a C6 to C24 aliphatic or alicyclic hydro-carbon and multiple hydrolyzable groups, wherein the organosilane is present in the hydrophobic agent at from about 1 wt % to about 20 wt %. The build material layer is exposed to energy to selectively coalesce the patterned portion and form a 3D object layer having a hydrophobic portion.

Abstract: In an example of a method for three-dimensional (3D) printing, a polymeric build material is applied to form a build material layer. A fusing agent is selectively applied, based on a 3D object model, onto the build material layer to form a patterned portion. A hydrophilic agent is selectively applied, based on the 3D object model, onto at least a portion of the patterned portion. The hydrophilic agent includes from 1 wt % to 12 wt % of a hydrophilic polymer dissolved in an aqueous liquid vehicle, wherein the hydrophilic polymer has a molar mass ranging from 1000 g/mol to 12,000 g/mol and is water-absorbent at a water to hydrophilic polymer weight ratio from 2:1 to 1000:1. The build material layer is exposed to energy to selectively coalesce the patterned portion and form a 3D object layer having a hydrophilic portion.