光沢

1. Origins, structure, and basic meaning

• Structure: 光沢 is read as こうたく and is a noun for luster, gloss, or sheen produced when light reflects from a smooth surface.
• Basic usage: Its return appears in 光沢が戻る, while its changing appearance appears in 光沢の見え方.

2. Common pitfalls and similar expressions

• Difference from 艶
  • Both can mean shine, but 光沢 more objectively describes reflected light and a material surface finish.
• Light and color
  • Gloss is not the color itself; its appearance can change with the angle of reflected light.