Copying focuses on the understanding of brushwork, not on accurate reproduction. When Wen Zhiming learned from Su Dongpo and Huang Tingjian, an elder told him, "Even if you can copy Su Like Dongpo's Yellow Valley, you are only following in the footsteps of others. Writing a stroke or dipping a word in ink is a taboo in calligraphy copying and calligraphy creation. But in copying, we can make up ink and adjust the front according to its situation. Regarding the paper size of copying copybooks, copywriters can choose independently. If the paper is big, he can copy more words.