Classification of Offset Printing Paper

Offset printing paper, commonly referred to as offset paper, is uncoated or coated paper used for offset lithography. It is typically supplied in rolls, though sheet forms are also available. Basis weight ranges from 60 to 150 g/m². The paper surface is bright white, smooth, and free of impurities; it exhibits good surface strength and tear length (generally no less than 3000 m), excellent ink absorption and dimensional stability, and does not curl or pill during printing. Manufactured by blending bleached chemical wood pulp with bleached chemical reed pulp in specific proportions, followed by separate refining. The mixture undergoes sizing, filling (with talc, kaolin, or titanium dioxide), and addition of other chemical additives before being formed on a fourdrinier paper machine. Coating may be applied subsequently. Used for printing books, covers, illustrations, and photographs.