Acid-Free – Having a pH of 7.0 or greater at the time of manufacture. Applies to paper/board products.
Lignin-Free – Must test negative for lignin, a component of plant cells believed to aid chemical degradation. Applies to paper/board products.
pH – The pH of the paper material at the time of manufacture; 7 is neutral; 0 to 6.9 is acidic, 7.1 to 14 is alkaline. Papers and boards usually test within a pH range. Plastics are not described by pH.
Construction – The thickness and type of material; pt. and mil are both terms that indicate 1/1,000 of an inch.
Color – Color is based on preference only and does not indicate archival-quality material. All of our boards and papers are archival quality unless we specifically note that the product is recommended for short-term storage only. Our colors do not bleed.
Buffer – This line indicates whether or not an alkaline substance has been added to neutralize acids or counteract acids in the future. Some items may be sensitive to alkalinity and require unbuffered materials. Learn more about buffered vs. unbuffered storage materials. Applies to paper/board products.
The Photographic Activity Test (P.A.T.) is a simulated aging test developed by the Image Permanence Institute to predict which storage materials will cause accelerated deterioration or staining in photos, a very sensitive medium. Most of our storage materials have been submitted and passed the test. Look for this logo in our catalog and on our website.
The absence of the logo does not indicate that a product has failed the P.A.T., as some products have not yet been tested.