Acid-free paper

Acid-free paper is paper that has had the acid pulp removed and is treated to be pH neutral (pH level above 7). This type of paper will usually be lignin free and will last between 50-100 years (depending on environmental factors) and is designed to preserve documents and art. Any decent notebook brand will use acid-free and pH neutral paper. As an example, newspaper is not acid or lignin free and will degrade over time.