The Librarian's Guide to Paper
In the 1980's, Xerox used the slogan "The Paperless Office." How things have changed! These days, the fastest growing segment of the pulp industry is paper for computers and Xerox now calls itself the "Document Company." Libraries are far from paperless as well, and more book titles are being printed and bound than ever, many in small quantities using advanced digital print technologies. There are many issues with paper but let's look at a few that bookbinders and librarians are particularly concerned about.
Paper Turns Yellow and Brittle. This is usually associated with acidity because the paper contains groundwood. Acid free paper is more scientifically called ph neutral paper and the paper industry has renamed it permanent paper. Although the American Library Association and librarians around the world have been successful in the past in urging publishers to use acid free paper, some publishers, to save costs, are now going back to using paper that contains groundwood.
Paper That is Wavy and Buckling. The most likely cause is that the paper grain is perpendicular to the spine. Unfortunately, there is nothing a bookbinder can do to correct this. Paper expands four to five times more in its width than it does in its length and changing environments swell and shrink fibers. But, fibers locked into the spine are unable to expand and shrink. The results are buckling on the fore edges. Another recent problem is that digital printing requires removal of all moisture from the paper. When this paper picks up moisture from the air, buckling may occur even if the grain is parallel to the binding edge.
Paper Grades. There are over a thousand different grades of paper yet we can sort them out to a very few types. First, there are very thin papers, which we measure with PPI's (Pages Per Inch). Bible paper is usually near 1600 PPI. Paper used for trade hardcover books is usually around 300 PPI. Children's books need more durable paper with exceptional tear strength. Coated paper is mainly used if there are color photos or illustrations. Twenty years ago, coated paper was about 20 percent filler, a clay-like mixture that is added to the pulp or is part of a coating. Unfortunately, today's publishers, to save costs, have reduced the fibers and increased the filling materials in coated paper to an average of 35 percent. If such paper gets wet, it is almost impossible to save the book.
How Paper Affects a Binding. Open some books and the pages "fight back" and try to return to their prone position. Most likely, the paper grain runs perpendicular to the spine. This situation is even worse when a thicker paper is used. Also, the first and last coated papers of a binding may become wavy when a book is cased-in to a cover. Moisture from the casing-in paste will penetrate through the endpaper and cause waviness. A binder can insert a moisture barrier, but with over a thousand different grades of paper, that expensive task is a difficult guessing game.
Despite its weaknesses and idiosyncrasies, paper is an invaluable part of our everyday lives. For decades, scientists have searched for solutions to replace paper and every time we hear of a new electronic paper breakthrough, the inventors are trying to imitate the "real thing." But, it looks like we will use the "real thing" for a long time to come.