Optical band gaps in photonic materials arise from the interference of light in periodic structures, with the simplest example being Bragg-reflection from a stack of planar layers. In 3D materials, the photonic band structure and therefore colour reflected from the material depend on the orientation and type of the periodic structure with respect to the incoming light, interferometrically reflecting light only along specific crystallographic directions. Creating a 3D photonic material which reflects light for all orientations is a substantial challenge as interferometric structures for visible light are too small for top-down manufacture and self-assembly methods cumbersome and delicate for the required 100-nm length scales. This project aims to harness polymer self-assembly combined with sol-gel chemistries to develop photonic materials with complete optical band gaps.