The behaviour of materials is governed by their microstructures, whether they are naturally occurring or artificially designed. Engineered microstructures lead to materials with new and useful functions, but their real-world application requires scalable microstructuring methods for production. This review discusses several principles of fabrication and their scalability. Replication by imprint and multiplexed probes are obvious candidates for scale-up, but they limit the choice of materials. The assembly of interacting particles is a promising, scalable fabrication method. A wide range of materials can be obtained as particles which assemble into regular superstructures, but large-scale structuring at high precision and yield as yet remains a challenge.