In handmade papermaking, are the chemical treatments ( e.g. boiling in soda ash, soaking bamboo in lime juice) necessarily for turning raw plant material into pulp? Or is the creation of the pulp just a mechanical process of breaking up the material with a "hollander beater" or some other machine? For example, the current Wikipedia article on lignin says that the paper used in making newsprint contains most of the original lignin in the plants. Does this imply that chemical treatments to dissolve lignin aren't needed to create pulp, if one is satisfied with producing paper that will yellow?