The raw material for paper cups is primarily paper. However, the specific type of paper used for making paper cups is known as cupstock or cup paper. Cupstock is a specialized grade of paper that is designed to meet the unique requirements of paper cup manufacturing, including strength, durability, and resistance to moisture and heat. Cupstock is typically made from a combination of virgin fibers and sometimes a small portion of recycled fibers. The virgin fibers are sourced from various types of trees, such as softwood or hardwood, depending on the desired properties of the paper. The specific fiber composition can vary among manufacturers and may be tailored to meet specific requirements. To enhance the performance of cupstock, various additives and treatments may be applied during the papermaking process. These additives can include sizing agents, which improve the paper's resistance to liquid penetration, and strengthening agents, which enhance its durability and stiffness. It's worth noting that cupstock is typically manufactured by specialized paper mills or converters that produce paper specifically for cup manufacturing. The paper is produced in large rolls or sheets and then further processed in paper cup-making machines to form the final cup shape.