The conservation of photographic and cinematographic documents is becoming a more urgent problem for the Centre de Recherches sur la Conservation des Documents Graphiques. A varied group of documents have to be conserved: daguerreotypes, ambrotypes, ferrotypes, calotypes, gelatino-argentic surfaces, thermocopies, electrocopies, vesicular and diazoic procedures. The first project was the study of black & white silver and gelatine surfaces on a support of tri-acetate of cellulose and polyester. In spite of the abundance of literature references on this subject, the authors have tried to investigate more thoroughly certain points considered most important. ln this report, a synthesis has been made of works already published adding the results of the authors' own experiences. The bibliographical data has been classified in three subjects: influence of the residual chemical products, influence of the environment and choice of the containers.