Reports on a research project to evaluate the Princeton University Library deacidification program through testing samples of paper treated since 1983; to describe the history of the program; to explain why operations have been scaled down; and to make future recommendations. The report covers the start-up of the program, production results, administrative concerns and problems, questions and observations about the deacidification agent used, Wei T'o, and a summary of the 1989 testing project results.