The current world record for folding a piece of paper in half belongs to Britney Gallivan, a high school student from Pomona, California, who folded a single piece of paper in half 12 times in 2002. Prior to her achievement, it was believed that folding a piece of paper in half more than eight times was impossible. Gallivan used tissue paper that was 4,000 feet (1,219 meters) long and derived mathematical equations for single and alternate direction folding to prepare for the challenge. She also wrote a book titled "How to Fold Paper in Half Twelve Times" detailing her equations. Since Gallivan set the record, others have made claims of folding a sheet of paper more than 12 times.