- Antiphonary A book containing the sung portion of the Divine Office.
- Border A painted design that surrounds the text and/or image. Partial borders will only frame a portion of the text and imagery while full borders will enclose the entire area on all sides. Borders can also be historiated or inhabited, featuring elaborate decorations of plant and animal life.
- Burnishing The process of polishing metal leaf to achieve a smooth and reflective sheen. The metal leaf is rubbed into the prepared surface using a hard stone like agate to achieve this brilliant effect. See also gilding.
- Choir Book A large format service book containing the parts of the Mass to be sung by the choir in cathedrals or churches. Music manuscripts were bound in large volumes so the entire choir could gather around the books to sing.
- Codex A manuscript volume, made up of folios that is then sewn together and bound as a book.
- Decorated initial An initial that comprises of non-figural decorative adornments.
- Divine Office Daily devotions celebrated by the clergy and members of religious orders.
- Drollery An amusing figure, often a grotesque, embellished in the margin of a manuscript page. Drolleries typically have no association to the written text.
- Facsimile A copy or reproduction of a manuscript that is made to be as true to the original source as possible. This differs from other forms of reproduction as facsimiles aim to replicate its given source as accurately as possible in terms of colour, scale, etc. Facsimiles have been used scholarly research and aid in the conservation of fragile objects like illuminated manuscripts.
- Flesh side The side of parchment of vellum that is generally whiter and smoother.
- Flourish Decorative penwork that emanates from an initial.
- Folio Deriving from the Latin wordfolium, which translates as ‘leaf’. Equivalent to a ‘page’, a folio is an individual leaf of a parchment or vellum. Illuminated manuscripts are numbered by leaves opposed to pages. Folding parchment or vellum in half makes two connected leaves, known as bifolium. See also Recto and Verso.
- Gilding The application of thin sheets of gold or silver leaf to a surface, carried out by an illuminator. See also burnishing.
- God the Holy Spirit The Holy Spirit is believed to be the third divine person in the Trinity with God the Father and God the Son being two other distinct persons. The Holy Spirit is often depicted as a white dove descending upon Christ and other figures in Christian imagery.
- Gradual A collection of chants or hymns sung during Mass for public, communal devotion. The name derives from the Latin word gradus meaning step as the practice of singing the verse responses on the steps of a raised pulpit.
- Grotesque A hybrid figure that combines elements from both human and animal forms. Like drolleries, these figures often bear no relation to the text.
- Hair side The side of parchment or vellum that can bear speckled traces of hair follicles and sometimes a darker, more yellow tonality. The animal species and preparation methods used on the skin can sometimes make the hair side and flesh side difficult to differentiate as the hair follicles can be removed through surface scraping.
- Historiated initial A letter that contains an identifiable figure(s) or scene that is relevant to the text.
- Hufnagel 'Horseshoe-nail', which are squared lines which alternate place on the red lines.
- Illumination Deriving from the Latin word illuminare, meaning ‘to enlighten.’ Illuminations are embellishments made of precious metals that add luminosity to manuscript designs.
- Illuminator An artist who creates illustrations within manuscripts. This includes initials, flourishes, etc. On occasion, the illuminator could also be the scribe of a manuscript but traditionally, these were separate roles.
- Leaf See folio.
- Line filler A decoration that fills out the remainder of a line of script.
- Liturgy The public rituals and observations of devotion as performed by a religious group. For medieval Christian liturgy, Mass and the Divine Office were principle acts of liturgical devotion.
- Marginalia Notes, diagrams, writing, or other marks made in the margins of a manuscript. Marginalia could be included in the original creation of the manuscript and by a later hand. Painted decorations can also be incorporated in the margins, see drollery and grotesque.
- Mass The celebration of the Eucharist.
- Miniature An independent illustration as opposed to a scene that is connected to a decoration like a border or initial.
- Parchment Writing support that is made of the untanned skins of animals primarily young sheep and goat. The skins are specially treated through the processes of soaking, dehairing, scraping, and tension drying to achieve the thin and flexible qualities desired by scribes. Parchment and vellum are often used as interchangeable terms as it is can be difficult to distinguish the skins used without detailed scientific analysis.
- Plainsong Also known as Gregorian chant, this refers to the body of single-line melody sacred music used in public ceremonies. Plainsong could be decorated with flourishes and miniatures.
- Pricking Small holes that have been made in regular intervals by a scribe with a knife or point alongside the edge of a folio to create guide rules for writing.
- Psalter A book containing the Book of Psalms to be used for daily devotions.
- Recto The front side of a folio, or right-hand page of an open book.
- Rubric Text such as a title or chapter heading that has been highlighted using red ink. Rubricating a text helps to identify its components.
- Scribe A person engaged in the physical copying of text within manuscripts and documents.
- Vellum Writing support that is made specifically of the untanned skins of young calves (veal). Vellum is also denoted for its higher quality, smoothness, and durability as compared to parchment. It was expensive and time consuming to prepare vellum and parchment for manuscript use. The skins often had faults and scarring but these areas were not wasted in the production process. Many manuscript leaves have holes because of flaws in the animal skins.
- Verso The back side of a folio, or left-hand page of an open book.