membrane

1. Origins, structure, and basic meaning

• Structure: 膜 is read まく, has 14 strokes, and relates to thin membranes or films.
• Basic usage: 膜 is read まく, and 皮膜 is read ひまく.

2. Common pitfalls and similar expressions

• 膜 and 皮膜
  • 膜 means membrane or film.
  • 温めた牛乳の表面に薄い膜ができた。 means “A thin film formed on the surface of the heated milk.”
  • 皮膜 means film or membrane.
  • 金属の表面に薄い皮膜が形成されていた。 means “A thin film had formed on the metal surface.”