What are the Half-Moon dividers in Large Books called?

September 4, 2006 5:15 PM

Is there a name for the semi-circle dividers found on the pages of larger books (dictionaries, encyclopedias, and/or bibles)?

Inspired by a recent FPP, my girlfriend and I were wondering if the dividers(?) pictured here have a specific name or term used to describe them. They make locating information so handy, I figured there was probably some name for them in the book manufacturing business.

posted by ktrey to Writing & Language (9 answers total)

I call it a thumb index. That may just be something I made up.
posted by sbutler at 5:21 PM on September 4, 2006

They're called "thumb indexes".
posted by solid-one-love at 5:22 PM on September 4, 2006

Best answer: thumb index
posted by shoesfullofdust at 5:23 PM on September 4, 2006

Gah. Meant to include a link. Thumb index.
posted by solid-one-love at 5:23 PM on September 4, 2006

Thumb indexes are also called cut-in indexes.
posted by jacquilynne at 5:25 PM on September 4, 2006

Response by poster: Thanks Everyone! I knew they had to have a name.
posted by ktrey at 6:19 PM on September 4, 2006

I've always heard "thumb tabs," rather than "thumb index."
posted by Violet Hour at 7:41 PM on September 4, 2006

"Thumb tab" is less-used, but also correct.
posted by solid-one-love at 7:55 PM on September 4, 2006

Best answer: Interestingly, "thumb indexes" at 835 only narrowly beats "thumb indices" at 648 in number of Google search results.

Irregular plurals turn me on.
posted by A Thousand Baited Hooks at 6:23 AM on September 5, 2006