Abstract: The present disclosure describes three-dimensional printing kits, three-dimensional printing systems, and methods of making three-dimensional printed objects. In one example, a three-dimensional printing kit can include a build material and a binding agent. The build material can include particles of copper or a copper alloy. The binding agent can include water, copper (II) nitrate or a hydrate thereof, and a reaction inhibition additive. The additive can be a copper oxide etchant, a water-soluble phosphate-containing compound, or a combination thereof.

Abstract: The present disclosure describes materials, methods, and systems for three-dimensional printing. In one example, a three-dimensional printing kit can include a fusing agent and a microbe-inhibiting agent. The fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation and convert the radiation energy to heat. The microbe-inhibiting agent can include a liquid vehicle and a metal bis(dithiolene) complex. The disclosure also describes methods of three-dimensional printing that utilize a metal-containing microbe-inhibiting material, which can be a metal bis(dithiolene) complex or other materials.