Shape-anisotropic polymeric micro-and nanoparticles are of significant interest for the development of novel composite materials, lock-and-key assemblies, and drug carriers. Currently, syntheses require external confinement in microfluidic devices or lithographic techniques associated with significant infrastructure and low productivity, so new methods are necessary to scale-up such production efficiently. Here we report bottom-up polymerization of regular shape-anisotropic particles (polygonal platelets with different numbers of edges, with and without protruding asperities, and fibrilar particles with controllable aspect ratios), with size control over 4 orders of magnitude (~50 nm-1 mm). Polymerization also enables the study of much smaller shapes than could previously be studied in water suspensions and we study the fundamental limits of the self-shaping transition process driving these transformations for monomer oil droplets of stearyl methacrylate (SMA) monomer oil. We show the method is compatible with a variety of polymerizing monomers and functional modifications of the particles (e.g., composites with magnetic nanoparticles, oil soluble additives, etc). We also describe post-synthetic surface modifications that lead to hierarchical superstructures. The synthesis procedure has great potential in efficient nano-manufacturing as it can achieve scalable production of the above shapes in a wide range of sizes, with minimum infrastructure and process requirements, and little maintenance of the equipment.