Friction feed paper folders use a roller to pull a sheet of paper into the machine and fold it. Friction feed paper folders are the most-commonly used paper folding machines. These paper folders are capable of folding thousands of sheets of paper per hour. Great for any school, church, or business. Air feed paper folders use a puff of air to lift a sheet of paper and pull it into the paper folder. Because air feed paper folders use air rather than friction to pull the paper in, air feed paper folders are ideal for use with glossy paper.