"Book-Plates" by W. J. Hardy is a treatise on the history and significance of book-plate collecting, written in the late 19th century. The book examines the evolution of book-plates from their introduction to modern examples, emphasizing their artistic and collectible value. Hardy addresses the moral concerns regarding book-plate collecting and provides insights into the various styles and historical context surrounding these owner's marks in books. The opening of "Book-Plates" begins with the author justifying the practice of collecting book-plates as a respectable and reasonable hobby, countering any accusations of immorality associated with it. Hardy reflects on his long-standing interest in this subject and highlights the growing number of collectors and enthusiasts in the field. He discusses the development of book-plate collecting in England, noting a lack of earlier works on the topic before the 1880s, and emphasizes the importance of proper treatment and arrangement for those who engage in this pursuit. The preface sets a scholarly yet personal tone, promising a mix of historical analysis and practical advice for collectors. (This is an automatically generated summary.)