Pen and ink dance refers to wonderful writing.
Good pen and ink means that the article is fluent and rich in content.
Mo Miao's brushwork is exquisite and his ink is clever. Describing calligraphy, painting, poetry and other techniques is ingenious and subtle.
Cordless ink: a tool used by carpenters to draw straight lines, which is a metaphor for laws and rules. Describe people's behavior or artistic style as free and easy, unrestrained and unrestrained.