Direct-Writing (DI) or Direct-Ink-Writing (DIW) technique facilitates the fabrication of three-dimensional (3D) colloidal structures through the layer-by-layer deposition of rheological controlled particle-dispersed-inks. This technique offers superiority due to free choices of particles. Various types of particles including nanomaterials such as CNTs and graphene have been printed successfully by DI technique. In addition to commercially available particles, it is also necessary to synthesize unique particles that are elements of emergence for 3D structural materials and devices. Herein, we present a facile and versatile platform approach for the syntheses of single-nanosized, nearly monodispersed micron-sized, and multicomponent nanosized particles, based on hydrolysis and polymerization under hydrothermal condition.