A broken inch of paper
Duancunzhi, Chinese idiom, Pinyin is Du à NJI à NC à nzh à, meaning incomplete painting and calligraphy. It's from Hua Ji.
The origin of Idioms
"The collection of ancient paintings can be cherished if there is no paper left in it," Volume I of painting inheritance by Deng Chun of Song Dynasty
Idiom usage
As an object or attribute; used in painting and calligraphy, etc.
A broken inch of paper
pay attention to important points - dà chù zhuó yǎn
beyond one 's reach or power to do something - lì yǒu wèi dǎi