A thumb index, also called a cut-in index or an index notch, is a round cut-out in the pages of dictionaries, encyclopedias, Bibles and other large religious books, and various sectioned, often alphabetic, reference works, used to locate entries starting at a particular letter or section. The individual notches are called thumb cuts.
Several ways to achieve this indexing effect were invented and patented in the 1970s by Arthur S. Friedman, a printing engineer in New York.
See also
References
"thumb index". Bookbinding and the Conservation of Books: A Dictionary of Descriptive Terminology. Foundation of the American Institute for Conservation. Retrieved 8 May 2012. http://cool.conservation-us.org/don/dt/dt3508.html ↩
Popular Mechanics. Hearst Magazines. Sep 1956. p. 184. https://books.google.com/books?id=peEDAAAAMBAJ&dq=%22index+notches%22+in+reference+books&pg=PA184 ↩
"Google Patents". patents.google.com. https://patents.google.com/?inventor=Arthur+S+Friedman&before=priority:19790101&after=priority:19690101 ↩