Wood pulp in the context of "Felt"

Paper is a thin sheet of matted cellulose fibers. Largely derived from lignocellulose, paper is created from a pulp dissolved into a slurry that is drained and dried into sheets. Different types of paper are defined by constituent fiber, paper pulp, sizing, coating, paper size, paper density and grammage.

The papermaking process developed in East Asia at least as early as 105 CE by the Han court eunuch Cai Lun, although archaeological evidence exists of 2nd century BCE paper-like material in China. Before the industrialization of paper production, the most common paper was rag paper, made from discarded natural fiber textiles collected by ragpickers. The 1843 invention of wood pulp, coupled with the Second Industrial Revolution, made pulpwood paper the dominant variety to this day.

Paper is a thin nonwoven material traditionally made from a combination of milled plant and textile fibres. The first paper-like plant-based writing sheet was papyrus in Egypt, but the first true papermaking process was documented in China during the Eastern Han period (25–220 AD), traditionally attributed to the court official Cai Lun. This plant-puree conglomerate produced by pulp mills and paper mills was used for writing, drawing, and money. During the 8th century, Chinese paper making spread to the Islamic world, replacing papyrus. By the 11th century, papermaking was brought to Europe, where it replaced animal-skin-based parchment and wood panels. By the 13th century, papermaking was refined with paper mills using waterwheels in Spain. Later improvements to the papermaking process came in 19th century Europe with the invention of wood-based papers.

Although there were precursors such as papyrus in the Mediterranean world and amate in the pre-Columbian Americas, these are not considered true paper. Nor is true parchment considered paper: used principally for writing, parchment is heavily prepared animal skin that predates paper and possibly papyrus. In the 20th century with the advent of plastic manufacture, some plastic "paper" was introduced, as well as paper-plastic laminates, paper-metal laminates, and papers infused or coated with different substances to produce special properties.

The wood industry or timber industry (sometimes lumber industry – when referring mainly to sawed boards) is the industry concerned with forestry, logging, timber trade, and the production of primary forest products and wood products (e.g. furniture) and secondary products like wood pulp for the pulp and paper industry. Some of the largest producers are also among the biggest owners of forest. The wood industry has historically been and continues to be an important sector in many economies.

Fiber crops are field crops grown for their fibers, which are traditionally used to make paper, cloth, or rope.Fiber crops are characterized by having a large concentration of cellulose, which is what gives them their strength. The fibers may be chemically modified, like in viscose (used to make rayon and cellophane). In recent years, materials scientists have begun exploring further use of these fibers in composite materials. Due to cellulose being the main factor of a plant fiber's strength, this is what scientists are looking to manipulate to create different types of fibers.

Fiber crops are generally harvestable after a single growing season, as distinct from trees, which are typically grown for many years before being harvested for such materials as wood pulp fiber or lacebark. In specific circumstances, fiber crops can be superior to wood pulp fiber in terms of technical performance, environmental impact or cost.

Cellulose is an organic compound with the formula (C
₆H
₁₀O
₅)
_n, a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the cell walls of green plants, many forms of algae, and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fibre is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%.

Cellulose is used mainly to produce paperboard and paper. Smaller quantities are converted into a wide variety of derivative products such as cellophane and rayon. Conversion of cellulose from energy crops into biofuels such as cellulosic ethanol is under development as a renewable fuel source. Cellulose for industrial use is mainly obtained from wood pulp and cotton. In addition, cellulose exhibits pronounced susceptibility to direct interactions with certain organic liquids, notably formamide, DMSO, and short-chain amines (methylamine, ethylamine), among other, are recognized as highly effective swelling agents.

Woodchips are small- to medium-sized pieces of wood formed by cutting or chipping larger pieces of wood such as trees, branches, logging residues, stumps, roots, and wood waste.

Woodchips may be used as a biomass solid fuel and are raw material for producing wood pulp. They may also be used as an organic mulch in gardening, landscaping, and ecosystem restoration; in bioreactors for denitrification; and as a substrate for mushroom cultivation.

A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods (kraft and sulfite processes). The finished product may be either bleached or non-bleached, depending on the customer requirements.

Wood and other plant materials used to make pulp contain three main components (apart from water): cellulose fibres (desired for papermaking), lignin (a three-dimensional polymer that binds the cellulose fibres together) and hemicelluloses, (shorter branched carbohydrate polymers). The aim of pulping is to break down the bulk structure of the fiber source, be it chips, stems or other plant parts, into the constituent fibers.