How do I clean the scanner glass to improve scan and copy quality?

Open the document cover and use a soft, dry, clean cloth to clean the surface of the scanner glass. If the glass is stained with grease or other hard-to-remove material, use a small amount of glass cleaner and a soft cloth, then wipe off all remaining liquid. Never use alcohol or thinner to clean the printer, as these chemicals can damage it, and do not press the glass surface too hard as scratching or damaging it will decrease scan quality. (Page 67)