Packaging Corporation of America (PCA), is a producer of containerboard and corrugated products in the United States. During the year ended December 31, 2008, the Company produced approximately 2.35 million tons of containerboard, of which about 80% was consumed in PCA's corrugated products manufacturing plants, 11% was sold to domestic customers and 9% was sold to the export market. PCA’s corrugated products manufacturing plants sold about 30.3 billion square feet (BSF) of corrugated products. As of December 31, 2008, it produced 1.44 million tons of kraft linerboard at its mills located in Counce, Tennessee and Valdosta, Georgia, and 0.91 million tons of semi-chemical corrugating medium at the Company’s mills located in Tomahawk, Wisconsin and Filer City, Michigan.