We stock 3 grades:
1. CHIPBOARD - pH neutral board contains acid but is .30 point thick and an excellent choice for short-term storage. White on one side. SUPER economical.
2. STANDARD ACID-FREE is acid-free all the way through. Acid-free board can trap migrating acids in paper and neutralize it. Use our .028 point board for intermediate to long-term storage. White on both sides.
3. SUPER ACID-FREE - **NEW Material** - Our .40 point thick board is off-white, 100% alpha cellulose board and buffered with calcium carbonate, which keeps the board from breaking down (indefinitely). Acid-free (alkaline 8.0-9.0), lignin-free, contaminant-free. Suitable for conservation. Meets the Library of Congress Archival Standards for indefinite storage.
Acid-free board can trap migrating acids in paper and neutralize it. Buffered board can stop migrating acids from entering an object and therefore prevent damage.