What are the artistic features of "Sacrifice to Yellow" in calligraphy?

"Several Pieces of Sacrifice to Yellow" is a eulogy written by Su Shi's brothers. Su Shi's calligraphy is mostly cursive. And this painting is purely a model method, simple and elegant, with strong brushwork and concise pen and ink, which can be said to be his masterpiece. Li Hongyi commented: "The opening of the letter ends, and there is a tendency to escape outside the word."