Collecting postage stamps related to a topic or a theme is an increasingly popular approach to philately or stamp collecting. The American Topical Association is the major philatelic organization devoted to the collection of stamps based on a topic or theme. Libraries are a sub-theme in the overall topical collecting area referred to as bibliophilately. The term "bibliophilately" was first used by George Eberhart in an article in American Libraries in June, 1982. Eberhart defines bibliophilately as the study of books and libraries on postage stamps. Eberhart's article in 1982, however, mostly focused on postage stamps featuring libraries and librarians. I got hooked on collecting library related postage stamps as the result of Eberhart's 1982 article and have since expanded my collecting interests to include library covers/envelopes, postal cards, and other items that I call postal librariana. I also published an article in American Libraries in February, 2000 entitled "Bibliophilately Revisited". A version of that article also appeared in The Whole Library Handbook 3. The Graphics Philately Association a sub-unit of the American Topical Association promotes the collecting of the history of books and printing on stamps.
Leona Rostenberg had earlier introduced the term "bibliately" in a series of articles in The American Philatelist in 1977. In addition to libraries, Rostenberg used the term "bibliately" to include postage stamps related to a broad range of book, printing, and library topics including primitive records, writing media, medieval calligraphy, alphabets, manuscripts, printing and printers, publishers, paper, book plates, books, literature and authors, illustrations, journalism, and book fairs.
The earliest discussion of libraries and librarians on postage stamps was an article by John Boynton Kaiser on "Librarianship and Philately" in Library Journal in July, 1955. Following that article Kaiser and John Henry Richter developed a list of librarians and archivists for an article in Topical Time (the magazine of the American Topical Association) in 1956. John Henry Richter who was the Librarian of the University of Michigan at Ann Arbor and a specialist in stamps relating to Judaica did extensive research on stamps that featured individuals who had worked in a library. He later joined with Hans Krol to publish lists of libraries and archives on postage stamps in Topical Time in 1979. Hans Krol who is a retired librarian in Hemsteede in the Netherlands continues to be an active collector of stamps depicting libraries and librarians and archives and archivists. He is also the founder of the Bibliotheekmuseum in Amsterdam.
Another serious collector of bibliophilately is Dr. Jerzy Duda in Cracow, Poland. Duda has developed a Web site on bibliophilately and is actively promoting this area of thematic philately. Duda includes in his definition of bibliophilately stamps related to schools, colleges, and universities as well postage stamps featuring libraries, books, and many of the areas identified by Rostenberg. Duda has exhibited parts of his collection in the Jagiellonian Library in Cracow and published a catalog of the exhibit.
J. Godsey maintains a blog devoted to "literary stamps" which would certainly be considered a category of bibliophilately. Many of the stamps on the site depict authors, bit there is a category for Books, Printing, and Libraries.
Dr. Heinz Gittig, now deceased, who served for 40 years as director of the German State Library in East Berlin published a sizeable catalog of libraries and their treasures on postage stamps in 2001.