定てい着ちゃく剤ざい

noun

fixing agent; fixer

Technical term in photography for a chemical that stabilizes developed images by removing unexposed silver halides.

• 写しゃ真しんを現げん像ぞうした後あと、定てい着ちゃく剤ざいで処しょ理りします。

  After developing the photo, we treat it with a fixing agent.