When storage materials are “buffered” it means an alkaline substance has been added to counteract the acids that may form in the future and to help absorb acids from artifacts. Alkaline-buffered storage materials usually have a pH of between 7.5 and 9. Most objects can be safely housed in unbuffered neutral pH material (with some exceptions). When in doubt about the type of enclosure or container to use, an unbuffered neutral pH enclosure is recommended. Read more about it and see a list of what items should be stored using buffered or unbuffered materials here- Buffered And Unbuffered Storage Materials.