What's the big deal about brittle books?
As the Western European population became literate, it created a demand for large-scale, popular publishing. It is estimated that 35 to 70 percent of the books published between the 1850s and the 1980s are brittle or will become so. If we do nothing to preserve the contents of those volumes, we will lose an enormous part of our history. When a brittle book crumbles to dust, there is nothing that can be done to reconstruct it or revitalize it. Thousand-year-old manuscripts may be in better in better condition than the paperback you bought for last summer's vacation.
Why is there acid in paper?
In wood-pulp paper produced mechanically, from the 1850s to the 1980s, the manufacturing process left chemicals that develop into several forms of acids. The three major contributors to acidity in books are the bleach used to make the paper white, the alum used to "size" the paper and keep the ink from bleeding, and the tannin used in the tanning of leather for bindings. As the paper ages, the acids form and sap strength from the paper, turning it brown and crumbly. Newspapers are printed on paper intended to be temporary; the aging process is quick and the discoloration can appear within days. Paperbacks from the 1960s and '70s are other good examples of the deterioration problem. Some publishers continue to use acidic papers in their books; others have made a commitment to offer permanent papers.
What is "permanent" paper?
"Permanent" paper meets the ANSI standard Z39.48-1992. It is made from cotton, or from chemically processed wood, with less than 1% lignin and an alkaline reserve of 2-3%. The minimum pH is 7.3. Papers labeled "acid-free" or "archival" may meet this standard, but more often have excess lignin and a inadequate alkaline reserve. Such papers will not remain acid-free. Books published on permanent paper may have that information printed on the title page verso, or display the lazy-eight symbol for eternity.
How long will recycled paper last?
It depends. Most recycled papers do not qualify as permanent papers. Some recycled paper is made from wood byproducts, some is made from reused paper. Any paper can be made more durable by the addition of a buffering agent, to stave off acid attack. However, the process of preparing recycled pulp shortens the fibers in paper, which is a key part of its strength. Whitening of recycled paper can leave residues that become acidic, and the commonly used bleaching processes cause the formation of dioxin, which is highly toxic and permeates the environment. You can, and should, use recycled paper anytime you don't plan to keep your paperwork. Just remember that it won't last long.
Why does it matter?
It doesn't matter, as long as what's on the paper is something you don't want to keep. When a research library buys a book, it intends to keep that book for its patrons for decades, perhaps even centuries. The acid in the book will eventually destroy it, even if the book is never taken off the shelf or read by anyone.
What can I do?
Support legislative efforts to require "permanent paper" be used for official publications. That will ensure that our government's records are still around for future historians. Choose permanent paper whenever you publish something that deserves to last.