The 1980 data point is an estimate based on two figures: 1) George Kelly's study (using a pH meter) of pH of books acquired by the Library of Congress Exchange and Gift Division in 1979 or 1980; and 2) the 1982 estimate by the CLR Committee on Production Guidelines for Book Longevity, of the proportion of paper manufactured in this country in 1980 for book production that was acid-free. The 1983 data point is from a study of the pH of paper in books received at Columbia University Libraries, reported in the Abbey Newsletter on p. 2 of the February 1984 issue. The last poimt is from a verbal report received in July from Akio Yasue and Elaine Harger, who have taken part in a follow-up study at the same institution. It will be published in this Newsletter soon.
Timestamp: Sunday, 03-Mar-2013 21:35:59 PST
Retrieved: Thursday, 24-Jan-2019 10:52:35 GMT