Woodfree uncoated paper
Introduction '''Woodfree uncoated paper''' ('''WFU'''), '''uncoated woodfree paper''' ('''UWF''') 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. 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. 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.
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