ABSTRACT
The 1980 International Antiquarian Book Fair had stringent security precautions. There was only one entrance utilized, bags and coats had to be checked, receipts were examined as customers left with their purchases, and plainclothes guards circulated. The Library of Congress has an ink which is said to be non-bleeding, nonacid, nonfading, and indelible. This ink is suitable for manuscripts. It is available to recognized institutions in either black or brown from the Library of Congress. Both the Research Laboratory of the British Museum and the Metropolitan Police Forensic Science Laboratory opt for the use in marking of pigments or suitable foils impressed with a countersunk die. Students at Oxford and Cambridge were found to be removing unmarked maps in large numbers from the collections. The most perfect marking system is of little use, however, if there are dealers who overlook the ownership, or others who are willing to do the same.
