A paintbrush is a brush you use to put paint on something — paper, a wall, a door, a model. The handle is wood or plastic; the head is hair or synthetic fibre. Size and shape change with the job: a fine tip for a picture, a wide flat brush for a wall. The word is plain and everyday. In art class it is the thing next to the water pot; in a hardware shop it is the thing next to the tin. English uses one word for both. People also say brush when the paint is already obvious, but paintbrush makes the job clear.

畫筆；油漆刷（畫畫用前者，粉刷牆壁用後者，英文是同一個詞）