In this thesis, we investigate the potential of self-organization for the fabrication of complex patterned materials. To study this potential, we investigate reaction-diffusion processes, where a delicate interplay between reaction kinetics and diffusion spontaneously induces pattern formation. Specifically, we develop fundamentally new principles for these processes and introduce two strategies to overcome diffusive limitations inherent to reaction-diffusion: mechanically responsive hydrogels and immersion controlled patterning. Both strategies enable the formation of user-defined, highly uniform patterns over large length scales. Subsequently, we demonstrate that patterns can be post-processed by applying photography inspired manipulation processes, to contour and convert patterns into user-defined shape and chemical composition. In summary, we show that reaction-diffusion driven processes can be applied for the formation of large-scale, highly uniform, tunable and customizable