In one aspect, build materials operable for use in 3D printing systems are described herein. In some embodiments, a build material comprises an oligomeric curable material, a reactive component that is solid at 25° C., and at least one diluent, wherein the reactive component comprises at least one chemical moiety that is polymerizable with a chemical moiety contained in the oligomeric curable material and/or the at least one diluent.