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.[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.