Permanent paper, definition

Most modern papers have a reasonable life expectancy of about 50 years. Permanent paper is paper that can have a reasonable life expectancy exceeding 200 years. The important phrase in this definition is reasonable life expectancy. Permanent paper is still a fragile commodity, and the papermaker has no control over paper processors and ultimate users or abusers. 

Definitions are urgently needed. For example, what is permanence An answer to this question for paper records is given in each of the four ASTM specifications for permanent-record papers. 

Finally, we turn to the relatively prosaic question of sources of information. We would have preferred to recommend only suitably advanced textbooks and articles in review journals and monographs. Somehow these sources appear more permanent than papers in the primary research journals, yet by definition secondary and tertiary sources of information are more dated. Wonders abound in all of them. We admit arbitrariness in our choices— no universal criterion for their inclusion other than the presence of exotic chemistry can be offered. There was too much, rather than too little, to choose among. After all, we were not allowed to write our own volume, The Encyclopedia of Exotica. We close the introduction with two quotes that provided us a guideline. The first is from a psalm that provides implicit chastisement for whatever choice we made the second is from the Mishnah, the legal core of the Talmud, which offers a source of reassurance for our efforts. 

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