Achieving nanoscale morphological control remains a major challenge in additive manufacturing due to the inherent kinetic mismatch between rapid Digital Light Processing (DLP) photopolymerization and the slow, thermodynamically driven self-assembly of block copolymers (BCPs). To address this limitation, we previously pioneered the integration of polymerization-induced microphase separation (PIMS) into 3D printing, providing an initial pathway toward the fabrication of nanostructured printed materials. This approach enabled the production of disordered nanostructures within complex 3D architectures, with potential applications in areas such as solid polymer electrolytes and advanced ceramic materials. In this talk, I will introduce recent advances in polymerization-induced nanostructure formation during 3D photopolymerization, demonstrating how careful control of resin formulation and photopolymerization conditions enables the direct fabrication of hierarchical materials with tunable ordered nanoscale morphologies, including lamellar and hexagonally packed cylindrical morphologies. This strategy opens new opportunities for bridging length scales in additive manufacturing and for designing functional materials with integrated nanoscale order.