A method of forming a part includes 3D printing a photopolymerizable resin and forming a preformed part and subsequently post-curing the preformed part with electron beams. The preformed part may be cured via UV curing. A section of the preformed part post-cured with electron beams may have a thickness of at least 1.0 centimeter, for example, at least 2.0 centimeters or at least 3.0 centimeters. An electron beam dosage to post-cure the preformed part may be between 10 kilogray (kGy) and 100 kGy. The preformed part may be 3D printed using stereolithography (SLA), digital light processing (DLP) or material jetting (MJ) and the photopolymerizable resin may include at least one of an acrylate functional polymer and a methacrylate functional polymer. In the alternative, or in addition to, the photopolymerizable resin may include at least one of a urethane, a polyester, and a polyether.