Immediately after the galvanizing process, a thin, transparent oxide film begins to form on the surface. This film is not visible to the naked eye, allowing the steel's metallic gloss to be seen. However, when the product is exposed to the atmosphere, a dense zinc oxide film forms more thickly, and the gloss gradually fades. The initial brightness (Munsell value) of approximately N7 changes to a gray color of N6 to N6.5.