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: 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: 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: An example of a three-dimensional (3D) printing kit includes a build material composition and a fusing agent to be applied to at least a portion of the build material composition during 3D printing. The build material composition includes a semi-crystalline or amorphous thermoplastic polymer having a predicted total dimension change during 3D printing ranging from about ?4% to about 9%. The fusing agent includes an energy absorber to absorb electromagnetic radiation to coalesce the semi-crystalline or amorphous thermoplastic polymer in the at least the portion. The fusing agent is a core fusing agent and the energy absorber has absorption at least at wavelengths ranging from 400 nm to 780 nm; or the fusing agent is a primer fusing agent and the energy absorber has absorption at wavelengths ranging from 800 nm to 4000 nm and has transparency at wavelengths ranging from 400 nm to 780 nm.

Abstract: An example of a dispersion includes cesium tungsten oxide nanoparticles, a zwitterionic stabilizer, and a balance of water. An example of a jettable composition includes cesium tungsten oxide nanoparticles, a zwitterionic stabilizer, a surfactant, a co-solvent, and a balance of water. A method for improving the stabilization of a jettable composition includes incorporating a zwitterionic stabilizer in the jettable composition, which includes the cesium tungsten oxide nanoparticles, the surfactant, the co-solvent, and the balance of water.

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: 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: Compositions including polyamides and methods of employing compositions including polyamides are described herein. For instance, composition for three-dimensional (3D) printing can include a polymer build material comprising of at least two polyamides including a first polyamide and a second polyamide, where the first polyamide is present in an amount ranging of from about 95% to about 99% of a total weight of the polymer build material and where the second polyamide is present in an amount ranging of from about 1% to about 5% of the total weight of the polymer build material.

Abstract: Compositions including polyamides and methods of employing compositions including polyamides are described herein. For instance, composition for three-dimensional (3D) printing can include a polymer build material comprising of at least two polyamides including a first polyamide and a second polyamide, where the first polyamide is present in an amount ranging of from about 95% to about 99% of a total weight of the polymer build material and where the second polyamide is present in an amount ranging of from about 1% to about 5% of the total weight of the polymer build material.

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: 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: 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: An example of a three-dimensional (3D) printing kit includes a build material composition and a fusing agent to be applied to at least a portion of the build material composition during 3D printing. The build material composition includes a semi-crystalline or amorphous thermoplastic polymer having a predicted total dimension change during 3D printing ranging from about ?4% to about 9%. The fusing agent includes an energy absorber to absorb electromagnetic radiation to coalesce the semi-crystalline or amorphous thermoplastic polymer in the at least the portion. The fusing agent is a core fusing agent and the energy absorber has absorption at least at wavelengths ranging from 400 nm to 780 nm; or the fusing agent is a primer fusing agent and the energy absorber has absorption at wavelengths ranging from 800 nm to 4000 nm and has transparency at wavelengths ranging from 400 nm to 780 nm.

Abstract: Compositions including polyamides and methods of employing compositions including polyamides are described herein. For instance, composition for three-dimensional (3D) printing can include a polymer build material comprising of at least two polyamides including a first polyamide and a second polyamide, where the first polyamide is present in an amount ranging of from about 95% to about 99% of a total weight of the polymer build material and where the second polyamide is present in an amount ranging of from about 1% to about 5% of the total weight of the polymer build material.

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: An example of a dispersion includes cesium tungsten oxide nanoparticles, a zwitterionic stabilizer, and a balance of water. An example of a jettable composition includes cesium tungsten oxide nanoparticles, a zwitterionic stabilizer, a surfactant, a co-solvent, and a balance of water. A method for improving the stabilization of a jettable composition includes incorporating a zwitterionic stabilizer in the jettable composition, which includes the cesium tungsten oxide nanoparticles, the surfactant, the co-solvent, and the balance of water.

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: The present disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of three-dimensional printing. In one example, a multi-fluid kit for three-dimensional printing can include a binder agent and an adhesion promoter agent. The binder agent can include water and latex particles in an amount from about 5 wt % to about 30 wt % based on the total weight of the binder agent. The adhesion promoter can include water and an adhesion promoter that includes catechol or a non-polymeric catechol derivative.