Paper production is basically a two-step process in which a fibrous raw material is first converted into pulp, and then the pulp is converted into paper. The harvested wood is first processed so that the fibres are separated from the unusable fraction of the wood, the lignin.
Related Theory
The pulping process is aimed at removing lignin without loosed fibre strength, thereby freeing the fibres and removing impurities that cause discoloration and possible future disintegration of the paper. Hemicellulose plays an important role in fibre-to-fibre bonding in papermaking. Several extractives such as waxes, resins are contained in wood but they do not contribute to its strength properties; these too are removed during the pulping process. In general, the softwoods (e.g., pines, firs, and spruces) yield long and strong fibres and hardwoods produce $a$ weaker paper as they contain shorter fibres.