Coatings can range from a matte finish to a high-gloss finish. Fully coated papers use a heavy layer of coating material that smoothes out the hills and valleys of a paper surface, creating a uniform print surface. Film-coated papers feature a very light coating that does little to smooth out the paper's surface. Filler Material, generally a mineral, added to pulp in order to enhance brightness or opacity. Fillers are commonly added to freesheet grades of paper to counteract the normal translucence of freesheet pulp.
Paper is made from cellulose fiber.
Lignin is the cement that holds the wood fiber together. In the chemical pulping process, the lignin is chemically dissolved leaving only the cellulose fiber. The term freesheet refers to the pulp being lignin-free. As the name implies, pulp manufactured by this method is produced by mechanically pulverizing the wood, usually by pressing logs against a rapidly revolving grindstone. In the groundwood process, the lignin remains with the fiber and becomes part of the paper.