Answer: Buffered materials have an alkaline substance – usually calcium carbonate – added to the material to counteract acids that may form in the storage material.

This durable B-Flute  Blue Corrugated Photo Storage Box comes with four equal compartments. It is made from acid-free, lignin-free material and has a 3% calcium carbonate buffer. Comes with metal-reinforced corners for stacking strength. Product Code: XPHOTO1215  https://www.bagsunlimited.com/product/6550/high-capacity-photo-box-holds-1700-photos