Letterpress paper is the main paper used in letterpress printing of books and magazines. Applicable to important works, scientific books, academic journals, textbooks for colleges and universities, etc. The letterpress paper can be divided into four grades of No. 1, No. 2, No. 3 and No. 4 according to the distribution ratio of the paper materials. The number of papers represents the quality of the paper. The larger the number, the worse the paper quality. Letterpress printing paper is mainly used for letterpress printing. The characteristics of this paper are similar to, but not identical to, newsprint. Since the ratio of paper pulp to pulp is better than that of newsprint, the fiber structure of the letterpress paper is relatively uniform, and the gap between the fibers is filled with a certain amount of filler and rubber, and is also bleached, which forms This paper has a good adaptability to printing. It is slightly different from newsprint. Although its ink absorption is not as good as newsprint, it has the characteristics of uniform ink absorption; water resistance and paper whiteness are better than newsprint. The relief paper has the characteristics of uniform texture, no lint, slight elasticity, opacity, slight water resistance and certain mechanical strength.