Processed Chlorine Free PCF is made using a 100% chlorine free manufacturing process, helping to preserve the environment and aquatic life from the hazards of chlorine waste. Both paper and packaging are made using post-consumer materials. The 20 lb basis weight and the 92 brightness are ideal for everyday use in copiers and printers. Acid-free for archival quality. Sheets Per Unit 5000; Machine Compatibility Copiers; Inkjet Printers; Laser Printers; Brightness Rating US 92.