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acanthus: A Mediterranean plant. The leaves are thick, fleshy, and scalloped. A stylization of the acanthus leaf began in Greek and Roman decoration, especially on the Corinthian capital, and became especially popular as a decoration in books of hours

Acanthus border from a 15th century book of hours

albumen: A class of simple, water-soluble proteins that can be coagulated by heat and are found in egg white, blood serum, milk, and many other animal and plant juices and tissues.

antiphonal: Also called antiphoner or antiphonary. Liturgical book containing antiphons, the sung portions of the Divine office, both texts and notation. Such books were often of a large format, to be used by a choir, and often included decorated and historiated initials

Square notation in a 13th century Italian antiphonal

ascender: The part of the letter above the body of the letter (t, d, b, l, k all have ascenders). 


barbs (of a quill): The thousands of soft 'branches' that spring out on either side of the shaft and angle toward the tip of the feather. Each barb has tiny parallel branches called barbules. See image below. The barbs should be trimmed when making a quill pen because they form a natural airfoil (that helped the bird fly) and cause unwanted resistance when writing. They can also get in the way of the writing hand. Primary flight feathers, which are most suitable for making quills, can be identified because they have a much narrower barb on one side of the shaft. 

barrel (of a quill): The hollow end of the feather shaft where it was attached to the bird, made of keratin. This part of the quill is cut to form the tip of the pen.


barrier cream:  A lotion that forms a protective barrier on the skin, helping guarding against the absorption of toxic materials such as dry pigments. Not a substitute for protective gloves and clothing.

binder: The "glue" the holds pigment together and makes it stick to a surface. Examples of binders include hide and fish glue, glair, egg yolk, oil, gums arabic and ammoniac, etc.

bole: A soft clay, available in several colors, but notably red and yellow, added to gesso for bulk, color, and flexibility. 

bone folder: A flat piece of bone or plastic, round at one end, pointed at the other. Used for scoring and folding paper. Can be held in the scribe's off-hand (not writing hand) for steadying the page; can also function as a burnisher for flat areas of gilding.

Bone folder

book arts: Typography, calligraphy, papermaking, bookbinding & related disciplines.

book of hours: Also called a primer or horae. This variation of the breviary was mostly used in private devotion. Its central text, the Little Office of the Blessed Virgin, is modeled on the Divine Office and represents a shorter version of the devotions performed in the eight canonical hours. The text, known from the tenth century, entered into lay use by the end of the twelfth century, often being attached to a psalter. 

burnish (gold): Rubbing metal leaf with specially-made tools to smooth and polish its surface. Burnishing tools can be made of haematite, psilomelanite, or most commonly, agate; they come in several shapes, needle point, dogtooth, and lipstick being the most common. See image below. Burnished leaf will ideally reach a shining mirror-finish.

Agate burnishers


crowquill: An old-fashioned dip pen with a fine metal point. Crowquill nibs have round bases and thus require their own nib-holders. They also require a very smooth writing surface, as the sharp point can otherwise catch in the fibers. They can be bought very stiff or very flexible, depending on the desired variation in line width. See image below.

Crowquill pen

descender: The part of the letter below the body (p, q, j, y all have descenders). 

diapering: From the French diapré (variegated). A repetitive geometric pattern, often used in the background of manuscripts and as a filler for empty spaces.

drolleries: Amusing figures or grotesque characters, often placed in the margins of illuminated manuscripts.

A drollery from a Bruges book of hours, 1494.

ductus: In calligraphy, the direction of strokes in letterforms, often designated by arrows around each letter in an exemplar. See images below.

dutching (a quill): Curing a quill by exposing the dampened barrel to a hot metal plate, such as a household iron, and shaping with a dutching hook. See image below.


exemplar: An alphabet in a lettering style; can be decorative or used for study. 

Exemplar of Gothic capitals Ductus of Gothic capitals


filler: Inert pigment added to paint to increase its bulk; also called extender. 

foliated (initial): An illuminated initial filled with decoration in leaf scrollwork.

flat gilding: The application of gold leaf to a flat size. This could mean water- or oil-based commercial sizes, or medieval sizes such as gum ammoniac, glair, or garlic juice. Flat gilding size is laid down in a thin layer, usually with a brush, and allowed to dry. It is then remoistened by slowly exhaling on it. It is best not to heavily burnish flat gilding, as the size often remains slightly flexible, and the pressure of burnishing could smear the gold. Consequently, it rarely achieves a high polish. Also see raised gilding.

flourish: A swirling, often freehand, embellishment to the basic letterform. Flourishes typically branch off of ascenders and descenders.


gall: The bulbous growths that form on the leaves and twigs of trees in response to attack by parasites; collected from oak, oak-apple and pistachio trees. Depending on the source, they can be amorphous in shape (Japanese and Chinese galls); large, smooth and globular (British and American oak galls); or small, round and spiky (Aleppo galls). See image below. They contain gallotannic acid, which, combined with iron (II) sulfate in aqueous solution, produces a greyish-black ink that further darkens as it oxidizes.

gesso: A preparation of primarily slaked plaster and a binder, used for raised gilding with metal leaf. Gesso is also used to prime canvas and wooden boards for painting. 

gesso grosso (thick gesso): Made with calcium sulfate (plaster of Paris). This is more suited to use on wood panels or masonry than in books. It is harder and stronger and holds up better to fill in between the grain of wood or rough spots on walls. It also has the ability to be carved or molded into shapes. The big drawback is that it dries rough, sometimes leaving small holes or pits.

gesso sottile (thin gesso):  Made with calcium carbonate. It shrinks as it dries, and clings to the underlying shape to produce a smoother texture. Book illumination didn't call for the heavy duty strength of gesso grosso; thin, smoother gesso was preferred. White lead and sugar were added to provide flexibility, so the gesso wouldn't crack as pages were turned.

gilder's mop: A soft round-headed brush used for transferring gold scraps and smoothing leaf onto prepared size. See image below. 

gilder's tip: A wide flat brush with a short handle, used for lifting loose leaf gold without ripping or wrinkling it, and transferring it to prepared size. See image below.

glair: A binder useful for painting and gilding. Made from whipped egg whites; beating to stiff peaks (as in meringue) breaks down the protein chains in the white and leaves you with a watery fluid.

glassine: A transparent, non-stick paper used in gilding; also known as crystal parchment. 

gloss: Words commenting on or translating those of the main text (often written in the margins or between lines).

grisaille: From the French gris (gray). Monochrome painting, often in gray, executed in a black pigment and an inert white pigment, and sometimes employing certain colors for highlights.

Grisaille from the Hours of Jean d'Evreux, 1320's


historiated (initial): An illuminated initial containing a narrative scene. 


illuminated initial: In manuscript illumination, a highly ornamented letter, usually the first letter of a word.

inert pigment: A non-reactive, neutralized pigment. Slaked plaster and chalk (calcium carbonate) are examples of inert pigments. For more information about neutralizing plaster, see my Kitchen Chemistry page and Recipes page.

inhabited (initial): An illuminated initial containing animals or human figures.


leaf: A single page of a manuscript. The front surface, which appears on the right side of a two-page opening, is called the recto, and the back surface, which appears on the left side is called the verso. Leaves are most often written on vellum, which can further be distinguished into flesh side and hair side.

ligature: The combination of two or more letters into a single character. For example, a + e = ĉ. To see some common Greek ligatures, look here.

line ending: Also line filler. Rectangular decorated block added to fill in awkward gaps of empty space left by short text lines. Aids in maintaining a visual unity to the textblock. 


majuscule: Writing in which all the characters are the same size regardless of whether they are upper case or lower case. See example below.

marginalia: Notes or doodles in the margins of a book.

miniature: In medieval Latin, miniare meant to work with minium, so one who worked in it was called a miniator, and the things that he was to miniate were called miniatura. So miniatures were originally the sections of a manuscript that were to be painted in red. Over time, as manuscripts were small and incidental, the word miniature came to mean diminutive and now refers particularly to separate illuminations within the body of the text.

minuscule: Writing in which there are different levels for upper and lower case letters. Below are examples of Artificial Uncial, a majuscule hand in use from approximately 500-999 AD, written on papyrus, and Carolingian Miniscule, in use from approximately 900-1150 AD. See example below.

Majuscule hand     Minuscule hand

muller: A flat-based ground-glass pestle for grinding pigments and gesso ingredients on a ground-glass or stone slab.


nap: Also called tooth. A slight surface texture of some writing surfaces, allowing the nib to grip the paper and the ink to sink slightly into the surface. Paper with no nap can be very difficult to write on.

nib: The writing tip of a pen or quill. Sometimes will have a metal reservoir attached above or beneath to hold ink for a longer stroke. 


palaeography: The study of ancient inscriptions and modes of writing; the art or science of deciphering ancient writings, and determining their origin, period, etc., from external characters.

parchment: A writing support material that derives its name from Pergamon (Bergama in modern Turkey), an early production center. The term is often used generically to denote animal skin prepared to receive writing, although it is more correctly applied only to sheep and goat skin. To produce parchment, animal skins were de-fleshed in a bath of lime, stretched on a frame, and scraped with a lunellum while damp. They could then be treated with pumice, whitened with a substance such as chalk, and cut to size. Also see vellum.

pigment: The coloring agent in paint. The paints used in illumination consist of vegetable, mineral, and animal extracts, ground or soaked out and mixed with a binding medium. Other additives were sometimes used, including stale urine, honey, and ear wax, to modify color, texture and opacity; inert whites such as chalk, eggshell, or white lead were added to increase opacity. During the early Middle Ages, scribes and illuminators ground and prepared their own pigments, but with the growth of specialized, more commercial production around 1200, they often purchased their ingredients in prepared form from a stationer or an apothecary. Today pigments are often made synthetically, and come premixed with binders in tubes and jars.

pounce: A substance like chalk, ash, powdered bone, or pumice, rubbed into a writing surface in order to improve it. Pounce can reduce greasiness, raise the nap, and whiten parchment. The term is also applies to a post-medieval technique employed in the transfer of an image--- punching holes in the pattern sheet and sprinkling pounce on it to reproduce a dotted outline on the sheet beneath.

pricking: Pinhole guides made with a sharp point or knife from which vertical and horizontal lines are drawn to frame the area for writing, music, or illumination.


raised gilding: The application of gold leaf to a gesso size, which gives the gold a raised appearance and allows for the possibility of direct burnishing. Also see flat gilding.

rubrication: From the Latin rubrica, red. The use of colored lines of writing were most often, but not always, written in red and served as instructional guides to the reader, providing descriptive headings and marking divisions in the text. Rubrication can also refer to the patterns of red dots often used around letterforms and decorations in Celtic illumination.

Rubricated title lines Patterns of rubricated dots in the Lindisfarne Gospels

ruling: Linear guide system for laying out page design and for establishing writing lines. Lines drawn from pinholes pricked in the writing material along the edges.

ruling pen: A simple metal pen made of two flat pointed pieces of metal which can be brought close together for fine lines or spread apart for wider lines; used for creating guidelines. Best used with a slightly raised ruler so that the ink does not feather.


serif: The foot on a letterform; the ending of or lead into a letter. 

size: An adhesive, generally a glue or resin—often mixed with a coloring agent and/or bulk agent—used to attach gold leafing to the illumination surface. Gesso and gum ammoniac are examples of medieval sizes. Size is also used in the making of paper, to prevent inks from bleeding; rubbing a sheet of rabbit skin glue across a troublesome writing surface will have a similar effect. 

shell gold: Powdered gold mixed with gum arabic into a kind of gold ink, and applied with pen or brush. So called because it was originally mixed and stored in shells.

shaft (of a quill): The solid, or mostly solid, center spine of the feather. Also called the "rachis." Strengthening struts run across the shaft's core like steps on a ladder. See image above. When choosing primary feathers for making quill pens, keep in mind that the shaft curves to the right on the bird's left wing, and vice versa. Right-handed writers should choose left wing-feathers.

square notation: One of the forms of neumes, or musical notation, used to denote melody. See image above.

staff: (pl. staves) Set of lines on which musical notes are written. Four-line staff is common since plainchant of the 12th c. Five-line staff for polyphonic use since early 13th c. See image above.


trompe l'oeil: French, meaning "deceives the eye." Describes painting in which things are made to appear to be resting on or projecting from the surface of the picture; a technique often used in the borders of Flemish books of hours.

A trompe l'oeil chrsyanthemum in the Horĉ Beatĉ Mariĉ ad usum Romanum


vellum: The skin of calf, kid or lamb prepared for writing or printing.

versal: The enlarged first letter of a word marking the beginning of a section of text. See image above.


zoomorphic (initial): An illuminated initial comprised of animal forms.