Here's a bit more about cardboard: Pulp is a fibrous material made from plant fibers through various processing methods. It can be categorized into mechanical pulp, chemical pulp, and chemical-mechanical pulp, depending on the process used; or into wood pulp, straw pulp, hemp pulp, reed pulp, sugarcane pulp, bamboo pulp, and rag pulp, based on the fiber source. It can also be classified into refined pulp, bleached pulp, unbleached pulp, high-yield pulp, and semi-chemical pulp, according to different purity levels. It is generally used in the production of paper and cardboard. Refined pulp, in addition to being used for special papers, is often a raw material for producing cellulose esters, cellulose ethers, and other cellulose derivatives. It is also used in man-made fibers, plastics, coatings, films, and other fields.