Additive manufacturing (3D Printing) has developed tremendous momentum in the past few years. It allows the user to build customized parts with unparalled complexity; all for a fraction of the cost compared to traditional manufacturing methods. However, steriolithographic and direct-write 3D printing are limited by the current material palette, as the majority of plastic parts do not meet the demands of high-performance applications. We present a novel innovation termed “3D magnetic printing”. This patented technique uses magnetic assembly with 3D printing to create discontinuous fiber composites that are constructed at the microscopic scale. This allows for unprecedented control over the internal structure of the printed part, leading to tunable mechanical, thermal, and optical properties that fit each application. Two functional prototypes have been developed and will be on display. Each prototype specializes in a different class of materials: photopolymers and colloidal dispersions. This work will demonstrate the successful recreation of complex bioinspired architectures that deliver enhanced material performance such as over %100 increases in strength, stiffness, and thermal conductivity compared to conventional parts. Numerous applications will be discussed, specifically focusing on the biomedical and aerospace industries where lightweight parts with high strength and fracture toughness are required but must meet very specific geometric constraints common in personalized orthotics, implants, and prosthesis.