Freedom Center is the massive plant where the Chicago Tribune--and many other newspapers--are printed. Until Freedom Center opened in 1981, the newspaper was printed in the Tribune Tower off Michigan Avenue. Enormous 1-ton rolls of paper are brought in by train and truck and stacked high in a cavernous warehouse. The rolls feed 10 large offset web printing presses, where cylinders with aluminum press plates and rubber blankets transfer ink to paper at blazing speeds. Inserting machines are then used to place millions of targeted advertising flyers into the newspaper for delivery.