The present disclosure is drawn to material sets and 3-dimensional printing systems that include a fusing agent. One example of a material set can include a fusing agent and a detailing agent. The fusing agent can include water, a carbon black pigment, and a water-soluble co-solvent in an amount from 20 wt % to 60 wt %. The detailing agent can include water and a black dye. In another example, a material set can include a fusing agent and a thermoplastic polymer powder.