隔层纸

Traditional (Taiwan): 隔層紙

gécéngzhǐ ㄍㄜˊ ㄘㄥˊ ㄓˇ

    • only a thin barrier apart
    • almost within reach

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
separated by a layer of paper
Meaning
Describes two things that are very close, or a barrier that is thin and easily broken, as when a result is almost reached. It can also mean that people are still divided by a lingering gap in understanding.

Sources