Kraft paper or kraft is paper or paperboard (cardboard) produced from chemical pulp produced in the kraft process.Sack kraft paper, or just sack paper, is a porous kraft paper with high elasticity and high tear resistance, designed for packaging products with high demands for strength and durability.Pulp produced by the kraft process is stronger than that made by other pulping processes; acidic sulfite processes degrade cellulose more, leading to weaker fibers, and mechanical pulping processes leave most of the lignin with the fibers, whereas kraft pulping removes most of the lignin present originally in the wood.