Photographic material in archives consists of negative and positive microfilm, prints on film or paper and possibly color films and prints. The various preventive measures necessary to keep them in good condition are outlined. The methods for restoring worn-out prints and negatives are also given. In three appendices that follow the text of the paper, the details of the test for residual hypo in processed films, of the Kodak Hyp Eliminator HE-1 and of the Kodak Gold Protective solution GP1 are also given. A list of references is provided at the end of the paper.