A study of incoming library books at the Columbia University Library indicates that about 40% of new hooks are printed on acid-free paper (i.e. over pH 6.7), and that 25% are on paper that carries an alkaline reserve--"buffered" paper. The reserve is important because it is the only practical way to maintain the pH of paper at a safe level. Without the alkaline reserve (recommended by the Library of Congress, NHPRC and the CLR Committee on Production Guidelines for Book Longevity as 2-3% calcium carbonate), environmental gases and acids produced as the paper ages cause the pH of the paper to drift downward as time goes on. As a result, even paper originally acid-free eventually becomes brittle.
The study did not test periodicals or older hooks, but it did include books manufactured outside the United States. Only a little over half of the books tested were American; a little over half of the American books were acid-free. Only 5% were identified by the publisher as acid-free.
All these figures have to be taken with a grain of salt, because the sample size to date is still very small. It was felt that it was methodologically more sound to sample a small proportion of books over an extended period of time, than to sample a larger proportion of books received in a brief period. The sample taken over a longer period of time is less likely to be biased by a surge of one particular type of book. The results obtained to date, however, are interesting enough that the authors felt that a preliminary communication was warranted. The sample to date consists of 103 books chosen randomly from a total of 1550 that passed through the processing department in a six-week period. The sampling problems were unusual, because the books were chosen not from the stacks but from book trucks delivered daily to the processing department. The figures above therefore must be viewed as exceedingly tentative and preliminary.
Even after making such allowances, however, it is most heartening to see that a great number of books produced today are on decent paper. It is reassuring, too, to see that American books were more likely to be acid-free and/or buffered than European books, because European papermakers are normally believed to be ahead of American papermakers in converting to the alkaline process. There were so few European books (23) in the sample, however, that this comparison must be viewed as little more than speculation.
Factors not examined that also have a bearing on the useful life of paper were paper strength (durability) and fiber quality.
It is intended that the study will be continued, and a much larger sample tested, so that more reliable figures will be obtained.
The method is fairly simple, aside from sampling and analysis problems. Basically it involves application of chlorophenol red with a thin brush to a page, to determine whether the pH is over 6.7, and punching out a small piece of paper, about as big as a typed capital letter, from each page found to be acid-free. The piece of paper is then tested for the presence of carbonate.
The test method used is a modification of the qualitative test described in ANSI/ASTM D 3290-76, Standard Specification for Bond and Ledger Paper for Permanent Records, and reprinted on the front page of the March 1983 issue of this Newsletter. In the original method, a fairly large paper sample is put into a test tube and observed with the unaided eye as 6N hydrochloric acid is poured over it, to detect effervescence. In the modified method used for this study, the tiny sample is placed on a glass dish under a microscope, the acid is dropped onto it with an eyedropper, another glass dish placed on top to get the sample into focus, and the observation made. Effervescence indicates the presence of carbonate. (The amount of carbonate, however, cannot be determined by this method.) The effervescence may be anything from spectacular little eruptions to slow seethings; there may be only one big bubble, or dozens or hundreds of smaller ones. Most of the action takes place in the first two or three seconds, but it continues for 20 to 200 seconds, depending on the thickness of the paper and other factors. With a good light and a 10 or 20 power magnification, observation is not only easy but entertaining.
Although this test for alkaline reserve needs to be refined in practice, it has several virtues that would allow libraries to monitor the quality of the books they buy, without having to hire chemists or destroy books in the process. First, the samples are small, and do not significantly disfigure the books; second, the results are fairly unambiguous, with almost all test samples showing either definite effervescence or none; and third, the materials are cheap (if one substitutes a loupe or magnifying glass for the microscope) and setup time is short.
In the survey itself and the trial run that preceded it, 44 publishers were found to have books with an alkaline reserve. Most of these 44 were commercial, not university, presses. Ten of the 44 were represented by two or more books; 8 of these 10 publishers used buffered paper consistently for the books sampled. They were:
University of California Press
Columbia University Press
Details of this study can be furnished on request; write Carolyn Harris, 110 Butler Library, or Michael Koenig, 516 Butler Library, both at Columbia University, New York, NY 10027.