Bifolio: A sheet folded in half to form two leaves or single folios. Several bifolios folded together form a quire (see definition below).

Colophon: An inscription, usually at the end of the text and containing information about the production of the manuscript, such as the date, the location, and the names of the scribe, artist, and patron.

Drollery: An amusing human, animal, or hybrid figure found in the margin of an illuminated manuscript.

Gesso: A composition of gypsum or chalk bound together with glue or egg white, often mixed with a red earth called Armenian bole. The gesso was applied to the manuscript with a brush, and served to cushion gold and silver leaf.

Gilding: The application of gold or silver to the surface of a manuscript, which was often laid onto gesso in the form of metallic leaf.

Hybrid: A part-human part-animal figure found in the margin of an illuminated manuscript.

Initial Word Panel: An enlarged and decorated word introducing a section of text.

Miniature: A picture in an illuminated manuscript.

Parchment: Animal skin prepared to receive writing or painting.

Pigment: A coloring substance of mineral, vegetable, or animal extracts that is mixed with water, egg, or gums to form paint.

Quire (or Gathering): A group of usually four bifolios assembled to form a booklet. A manuscript is typically composed of several quires sewn and bound together.

Recto: The front side of a folio, appearing on the left side of an opening of a Hebrew manuscript book.

Rahit (pl. rehitim): A liturgical poem composed of verses in alphabetical order with key words repeated at the beginning and/or end of each line.

Ruling: Preparing a blank manuscript page for writing by defining the margins and rows with vertical and horizontal lines.

Verso: The back side of a folio, appearing on the right side of an opening of a Hebrew manuscript book.

Zoomorphic: Representing or imitating animal forms in decorative art.

Michelle P. Brown, Understanding Illuminated Manuscripts: A Guide to Technical Terms (Malibu: J. Paul Getty Museum in association with the British Library, 1994); Christopher De Hamel, The British Library Guide to Manuscript Illumination: History & Techniques (British Library Guides) ( Toronto: University of Toronto Press, 2002).