Embodiments of the invention are directed to softening amorphous polymeric materials based on a combination of thiol, acrylate, ene and epoxy monomers. These materials can soften to the modulus of tissue, have a sharp transition and are highly tunable. The materials have a glassy modulus of 1-7 GPa and exhibit a rubbery plateau in modulus that can range from 100 MPa down to as low as 0.03 MPa, which is at or below the modulus of tissue. They have potential uses as materials for near net shape processing such as casting, stereolithography, reaction injection molding, fused deposition molding and various other forms of 3D printing.