brightening agent; glazing agent; polishing agent
Technical term used in manufacturing, cosmetics, food, and coatings to add shine or gloss.
This car wax contains a polishing agent.
Glazing agents are sometimes used as food additives.
添加剤 is a general term for additives; 光沢剤 is a specific type used for gloss.
Compound of 光沢 (luster, gloss) and 剤 (agent, preparation).