Peter Waters, considered the father of modern book conservation, was the conservation coordinator at the National Central Library after the 1966 flood of the Arno in Florence, Italy, and was accompanied by hundreds of conservators from around the world.[21][22] Before the flood, library conservation was not yet an established field.[23] The water affected one-third of the library collections including periodicals, newspapers, fine prints, maps, posters, and the Magliabechi and Palatine rare-book collections.[24] The flood broke the tradition of maintaining proprietary trade secrets and conservation treatments as the disaster necessitated the collaboration of the world's most experienced book and paper conservators.[24] One book and paper conservation technique that resulted from this collaboration was the development of the "heat-set tissue" paper mending.[25] Another development from the Florence floods was the study of limp vellum binding and its usefulness in conservation due to its resistance to water damage.[26] Experienced in large scale archival disasters, Waters defined seven essential requirements for successful recovery after the flood.[21] The first publication of a standard of practice for conservators was published in August 1964 in Studies in Conservation by the International Institute for Conservation American Group, now the American Institute for Conservation (AIC).