Woodfree uncoated paper

Not to be confused with Tree-free paper.

Woodfree uncoated paper (WFU) or uncoated fine papers are manufactured using wood that has been processed into a chemical pulp that removes the lignin from the wood fibers and may also contain 5–25% fillers.^[1] Both softwood and hardwood chemical pulps are used and a minor part of mechanical pulp might be added (often of aspen or poplar). These paper grades are calendered.

Properties

Woodfree uncoated papers are of high quality and have a natural look and feel. The properties are good strength, high brightness and good archival characteristics.^[2] 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 bibles (hence the name Bible paper) and dictionaries.

References

↑ The paper made without using mechanical pulp
↑ Paulapuro, Hannu (2000). "1". Paper and Board grades. Papermaking Science and Technology. 18. Finland: Fapet Oy. pp. 35–37. ISBN 952-5216-18-7.

Paper

History Manufacture/Papermaking

Types	Blotting Bond Construction Cotton Rag Crêpe Display Dó Asphalt Glassine India Korean Kraft Laid Manila Newsprint Oatmeal Onionskin Origami Baking Building Rice Rolling Security Seed Copy Tar Thermal Tissue Tracing Transfer Tree-free Wallpaper Washi Waterproof Wax Wood-free Wove Writing Xuan

Materials	Fiber crop Paper chemicals Papyrus Wood pulp Algal bloom (Shiro alga carta)

Specifications	Grammage Density Size Units of paper quantity Surface chemistry of paper Wet strength

Manufacture and process	Bleaching of wood pulp Calender Conical refiner Deinking Paper pollution Environmental impact of paper Hollander beater Kraft process Organosolv Paper cut Paper machine Paper recycling Soda pulping Sulfite process

Industry	Paper industry In Europe In Canada In India In Japan In the United States Paper mill List of paper mills

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