Three-dimensional printing with pigment reactants

A method of making a three-dimensional printed article comprising:

• iteratively applying individual build material layers of polymer particles to a powder bed;
• based on a three-dimensional object model, selectively jetting a fusing agent onto the individual build material layers, wherein the fusing agent comprises water and a radiation absorber;
• based on the three-dimensional object model, selectively jetting a first reactive agent onto the individual build material layers, wherein the first reactive agent comprises water and a dissolved first pigment reactant, and wherein the dissolved first pigment reactant includes FeSO4, NaOH, Na2SO4, BaCl2, CuSO4, NaHCO3, Na2CO3, Na2CrO4, K2CrO4, ZnSO4, ZnCl2, or K3[Fe(CN)6];
• based on the three-dimensional object model, selectively jetting a second reactive agent onto the individual build material layers, wherein the second reactive agent comprises water and a dissolved second pigment reactant, and wherein the dissolved second pigment reactant includes FeSO4, NaOH, Na2SO4, BaCl2, CuSO4, NaHCO3, Na2CO3, Na2CrO4, K2CrO4, ZnSO4, ZnCl2, or K3[Fe(CN)6];
• reacting the second pigment reactant with the first pigment reactant to form a water-insoluble pigment, wherein the water-insoluble pigment includes iron oxide red, barium white, basic copper carbonate, zinc chrome yellow, or Prussian blue;
• and
• exposing the powder bed to energy to selectively fuse the polymer particles in contact with the radiation absorber to form a fused polymer matrix at individual build material layers.