The biography and typography of William Caxton : England's first printer (1877)
Blades, William, 1824-1890 · London : Trübner · leaf 163
A Quaternion—Four sheets of paper folded in half,quirewise, or one inside another. This gives eight leaves,or sixteen pages. k2 1S2 WILLIAM CAXTON. … If this arrangement be kept in mind it will be found veryuseful in many ways. For instance, it is often important toknow whether a leaf preceded the first printed page, and, ifso, whether the blank leaf found in many volumes is thatleaf. It is plain that if a quaternion was adopted for thefirst…
Caxton, William, ca. 1422-1491 · Printing · Printers -- Great Britain · Printing -- England Origin and antecedents
Internet Archive · University of Toronto, Robarts Library · Public Domain Mark 1.0. Free to use for anything.