Full‐Color Generation via Phototunable Mono Ink for Fast and Elaborate Printings

Abstract Unlike pigment‐based colors, which are determined by their molecular structure, diverse colors can be expressed by a regular arrangement of nanomaterials. However, existing techniques for constructing such nanostructures have struggled to combine high precision and speed, resulting in a narrow gamut, and prolonged color fabrication time. Here, this work reports a phototunable mono ink that can generate a wide range of colors by controlling regularly arranged nanostructure. Core–shell growth controlled by polymerization time precisely regulates the distance between arranged particles at a nanometer‐scale, enabling the generation of various colors. Moreover, the wide and thin arrangement induces constrained out‐of‐plane growth, thus facilitating the intricate color generation at the desired location via photopolymerization. Upon terminating polymerization by oxygen gas, the generated colors are readily fixed and kept stable. Utilizing programmed ultraviolet illumination, large‐scale and high‐resolution (≈1 µm) full‐color printings are demonstrated at high speed (100 mm 2 s −1 ).