Folio​

​A type of book format, where the full sheet of paper is only folded once. A full sheet of paper will have four "pages" of text, two "pages" on each side, which is then folded down the middle.[1] 

​Click here to see a diagram.

Incunabula

​The term for an early printed book, "in cunabulis (in the swaddling clothes) of the new-born art of printing."[2] A book printed from the beginning of the invention of the printing press in the early 1440s until 1501. 

Incipit

​The first words of a text. Before the development of titles and title pages, a text would be identified by its incipit. It is Latin for "it begins".

Manuscript

Meaning that the item was hand written, not created through mechanical printing (i.e. printing press).

Pamphlet

A smaller, yet complete work. Usually bound in a soft cover.

Parchment

Stretched and scraped goat or sheep's skin used for writing. 

Rubrication

Rubrication is the use of red ink in some parts of a manuscript, as opposed to black ink. Primarily used to indicate a point of interest, a new paragraph, or a new section. 

[1] Carter, "John Carter's ABC for Book Collectors," 122..

[2] Carter, "John Carter's ABC for Book Collectors," 147.