Defining Rareness

The "rareness" of a text may be a function of the age of the text, the physical aspects of its production (such as binding, illustrations, etc.), the number of copies produced and still available, the status of the book’s owner, and so on. The Rare Books and Manuscript Section of the Association of College and Research Libraries hosts a very useful website that answers many questions about identifying and defining the “rareness” of books. 

See Your Old Books .