The present disclosure is drawn to 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 first reactive agent can include a first liquid vehicle and an epoxy compound having multiple epoxide groups. The second reactive agent can include a second liquid vehicle and an amine compound having multiple amino groups.

The present disclosure is drawn to 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 first reactive agent can include a first liquid vehicle and an epoxy compound having multiple epoxide groups. The second reactive agent can include a second liquid vehicle and an amine compound having multiple amino groups.

An example of a multi-fluid kit for three-dimensional (3D) printing kit includes a fusing agent and a build material reactive functional agent. The fusing agent includes water and an electromagnetic radiation absorber. The build material reactive functional agent includes a vehicle and trifluoroacetic anhydride. The multi-fluid kit may also be part of a 3D printing kit.

An example of a multi-fluid kit for three-dimensional (3D) printing kit includes a fusing agent and a build material reactive functional agent. The fusing agent includes water and an electromagnetic radiation absorber. The build material reactive functional agent includes a vehicle and trifluoroacetic anhydride. The multi-fluid kit may also be part of a 3D printing kit.

An example of a jettable antioxidant formulation is for three-dimensional (3D) printing. The jettable antioxidant formulation includes an antioxidant blend; a surfactant, a dispersant, or a combination thereof; a water soluble or water miscible organic co-solvent; and water. The antioxidant blend consists of a primary antioxidant and a secondary antioxidant.

An example of a jettable antioxidant formulation is for three-dimensional (3D) printing. The jettable antioxidant formulation includes an antioxidant blend; a surfactant, a dispersant, or a combination thereof; a water soluble or water miscible organic co-solvent; and water. The antioxidant blend consists of a primary antioxidant and a secondary antioxidant.

A pulverulent composition for the manufacture of articles having a metallic appearance that is stable over time and an improved resistance to penciling, the composition including: from 50 to 99.9% by weight of at least one thermoplastic polymer, from 0.1 to 5% by weight of at least one effect pigment, from 0 to 0.3% by weight of at least one metallic pigment relative to the total weight of the composition.

A pulverulent composition for the manufacture of articles having a metallic appearance that is stable over time and an improved resistance to penciling, the composition including: from 50 to 99.9% by weight of at least one thermoplastic polymer, from 0.1 to 5% by weight of at least one effect pigment, from 0 to 0.3% by weight of at least one metallic pigment relative to the total weight of the composition.

A three-dimensional printing method can include iteratively applying polymer build material as individual layers; based on a three-dimensional object model, selectively jetting an electromagnetic radiation absorber and a translucency-modulating plasticizer onto individual layers of the polymer build material; and exposing the powder bed to electromagnetic energy to selectively fuse portions of individual layers of the polymer build material together to form a three-dimensional object. The polymer build material can include from about 60 wt % to 100 wt % polymeric particles having an average particle size from about 10 ?m to about 150 ?m and a degree of crystallinity from about 2% to about 60%, to a powder bed. At the locations where the polymer build material includes jetted translucency-modulating plasticizer, the three-dimensional object can exhibit an optical transmittance from about 5% to about 80%.

A three-dimensional printing method can include iteratively applying polymer build material as individual layers; based on a three-dimensional object model, selectively jetting an electromagnetic radiation absorber and a translucency-modulating plasticizer onto individual layers of the polymer build material; and exposing the powder bed to electromagnetic energy to selectively fuse portions of individual layers of the polymer build material together to form a three-dimensional object. The polymer build material can include from about 60 wt % to 100 wt % polymeric particles having an average particle size from about 10 ?m to about 150 ?m and a degree of crystallinity from about 2% to about 60%, to a powder bed. At the locations where the polymer build material includes jetted translucency-modulating plasticizer, the three-dimensional object can exhibit an optical transmittance from about 5% to about 80%.