Additive manufacturing has the potential to change medicine, but clinical applications are limited by a lack of resorbable, printable materials. Herein, we report the first synthesis of polylactone and poly(propylene fumarate) (PPF) block copolymers with well-defined molecular masses and molecular mass distributions using sequential, ring-opening polymerization and ring-opening copolymerization methods. These new copolymers represent a diverse platform of resorbable printable materials. Furthermore, these polymers open a previously unexplored range of accessible properties among stereolithographically printable materials, which we demonstrate by printing a polymer with a molecular mass nearly 4 times that of the largest PPF homopolymer previously printed. To further demonstrate the potential of these materials in regenerative medicine, we report the postprinting "click" functionalization of the material using a copper-mediated azide alkyne cycloaddition.