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.