Woodfree uncoated paper (WFU), uncoated woodfree paper (UWF) or uncoated fine papers are manufactured using wood that has been processed into a

chemical pulp Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemical or plant-based additives, pulp is the major raw mate ...

that removes the

lignin Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity ...

from the wood fibers and may also contain 5–25% fillers.The paper made without using mechanical pulp
/ref> Both

softwood Scots Pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. The main differences between hardwoods and softwoods is that the s ...

and

hardwood Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes fro ...

chemical pulps are used and a minor part of

mechanical pulp Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemical or plant-based additives, pulp is the major raw mate ...

might be added (often of

aspen Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section ''Populus'', of the ''Populus'' genus. Species These species are called aspens: *'' Populus adenopoda'' – Chinese aspen (Chin ...

or poplar). These paper grades are

calendered A calender is a series of hard pressure rollers used to finish or smooth a sheet of material such as paper, textiles, rubber, or plastics. Calender rolls are also used to form some types of plastic films and to apply coatings. Some calende ...

Properties

Woodfree uncoated papers are of high quality and have a natural look and feel. The properties are good strength, high

brightness Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, ...

and good archival characteristics. They provide a non-glare surface suitable for reading and writing.

Special types

''Offset paper'' is a WFU paper with ISO brightness > 80% and a basis weight of 40–300 g/m². Surface strength and low linting are the main parameters, but brightness and opacity are also important. ''Lightweight offset paper'', also called onionskin, has a basis weight of 25–40 g/m² and are normally used for

bible The Bible (from Koine Greek , , 'the books') is a collection of religious texts or scriptures that are held to be sacred in Christianity, Judaism, Samaritanism, and many other religions. The Bible is an anthologya compilation of texts o ...

s (hence the name

Bible paper Bible paper, also known as scritta paper, is a thin grade of paper used for printing books which have many pages, such as a dictionary. Technically, Bible paper is a type of woodfree uncoated paper. This paper grade often contains cotton or li ...

) and dictionaries.

References

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