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: 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: The present disclosure relates to a composition for printing a three-dimensional object. The composition comprises composite particles comprising a thermoplastic 5 polymer and a colour-masking pigment. The colour-masking pigment is encapsulated by the thermoplastic polymer and is present in an amount of from about 1.5 to less than about 6 wt % of the total weight of the composite particles.

Abstract: This disclosure describes three-dimensional printing kits, methods, and systems for three-dimensional printing with directionally-dependent reflective particles. 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 directionally-dependent reflective particles. The directionally-dependent reflective particles can be chemically and thermally stable at a melting point temperature 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: A materials kit for 3D printing can include a powder bed material including from about 60 wt % to 100 wt % composite fibers having an average aspect ratio from about 3:1 to about 30:1 and a fusing agent including an energy absorber to absorb electromagnetic radiation to produce heat. The composite fibers can include glass fibers coated with an encapsulating polymer, wherein the glass fibers can be included at from about 5 wt % to about 40 wt % based on the total weight of the powder bed material.

Abstract: In some examples, a method measures values of a property of a build material aged in a heated environment, and computes, using a predictive model for each of a plurality of recyclability ratios, output values of the property over a plurality of generations of the build material, each recyclability ratio of the plurality of recyclability ratios representing relative amounts of fresh build material and used build material. The method further includes presenting the output values of the property over the plurality of generations to enable selection of a recyclability ratio to use in building a part using the build material.

Abstract: The present disclosure relates to a composition for printing a three-dimensional object. The composition comprises composite particles comprising a thermoplastic 5 polymer and a colour-masking pigment. The colour-masking pigment is encapsulated by the thermoplastic polymer and is present in an amount of from about 1.5 to less than about 6 wt % of the total weight of the composite particles.