Researchers at Kobe University have developed a new type of coating using silicon nanospheres that can provide glossy, long-lasting color on three-dimensional surfaces. This innovation could revolutionize how colors are applied in industries ranging from automotive to aerospace. Traditional color coatings often rely on thick layers of pigment, which can fade over time and add considerable weight. In contrast, structural color—like the iridescent shimmer seen in peacock feathers—does not fade with light exposure. However, it has its own challenges, such as changing color depending on the viewing angle and being incompatible with protective layers that are necessary for durability. Hiroshi Sugimoto, a materials engineer at Kobe University, previously introduced silicon nanospheres as a way to achieve structural color without the issues of iridescence. Recently, his team made a breakthrough by using inkjet printing to apply these nanospheres. However, the color produced was not glossy—it was more diffuse. The key to achieving glossiness came from packing the nanospheres inside silica shells. This not only protects the particles but also controls their spacing, enabling them to self-assemble into neat, uniform arrays. This arrangement reduces the diffuse reflectance, resulting in a glossy, angle-independent color. In a study published in the journal Small Structures, Sugimoto's team demonstrated that their new coating can be applied to large 3D surfaces while maintaining a glossy finish. They also found that adding a protective layer did not alter the color significantly. This development marks a significant step forward in making structural color coatings practical for real-world use. The coatings are extremely lightweight, and a single layer of silicon nanospheres can achieve high brightness and opacity. If used on large aircraft, for example, it could reduce the weight of the aircraft’s exterior coatings from hundreds of kilograms to just a few hundred grams—lighter than a single carton of milk for the entire plane. The materials used—silicon and silica—are both abundant and non-toxic, with silicon being available from the semiconductor industry and silica being a common component of Earth's crust. These properties make the coatings more sustainable and resource-efficient. Sugimoto is now working on establishing a company to bring this technology to industrial scale. The process is compatible with large-scale coating techniques like spray coating and roll-to-roll printing. Looking ahead, Sugimoto aims to expand the application of these silicon nanoparticles to include additional optical functions such as sensing, photocatalysis, and energy management, opening up a wide range of possibilities for multifunctional materials.