Charta (pl. chartae) (English: page)
Each leaf of a manuscript, having two faces or sides; c. recto: the front face, or right side; c. verso: the back face, or left side.
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A gathering, or quire, of two sheets folded to produce four chartae, eight sides.
Quaternion
A gathering, or quire, of four sheets folded to produce eight chartae, sixteen sides.
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