The Profession of Illuminator

Illumination is the art of adorning manuscripts with painted and gilded decorations, from the Latin “illuminare” (to illuminate, to bring to light).

Practiced since Antiquity in Egypt and Greece, it reached its peak in the Western Middle Ages. From the 8th to the 13th century, monasteries became the main centers of production, with monk-illuminators working in workshops called scriptoria.

In the 13th century, the activity gradually became secularized with the rise of cities and universities. Urban workshops developed, led by masters who trained apprentices according to guild rules.

The end of the 15th century marked a turning point with Gutenberg’s invention of printing, which led to the gradual decline of manuscript illumination. However, some luxury books continued to be illuminated for wealthy people.

After a long period of neglect, illumination experienced renewed interest from the late 19th century in intellectual circles with the development of codicology (see glossary). Today, the practice of this art has not completely disappeared and some artists perpetuate the knowledge and skills of medieval illuminators.

The Main Tasks of the Profession

The illuminator works mainly on parchment (calfskin, sheepskin or goatskin) previously prepared. Their work includes several stages:

1. Preparation of materials: grinding pigments, preparing binders and glues.

2. Sketching with lead or silver point, which traces the outlines of the motifs.

3. Application of gold leaf (hence the term “illumination,” from the Latin “illuminare”: to bring to light).

4. Application of colors, prepared with binders such as egg white (tempera), gum arabic or glue.

5. Finishing touches with precise details such as faces and ornaments.

An illuminator masters different decorative styles: ornate initials, vegetal borders, historiated scenes, and drolleries (small humorous scenes in the margins). This artistic craft requires patience, precision and thorough knowledge of traditional techniques and materials.​​​​​​​​​​​​​​​​

The Parchment

Parchment is a writing support obtained from animal skins, primarily sheep, calf (vellum), or goat. Its manufacture, perfected since Antiquity, comprises several meticulous steps.

Parchment presents ideal characteristics for copying and illumination:

Durability: unlike papyrus or paper, it resists folding and time.

Double-sided: it can be written on both sides if prepared on both faces.

Suitable surface: its texture allows good adhesion of inks and pigments.

To prepare a manuscript, parchment was :

1. Cut into sheets of the desired size

2. Ruled with lead point to guide the writing

3. Folded and assembled into gatherings (quaternions)

The copyist worked first, tracing the text and reserving spaces for the illuminator. The latter then intervened by applying gold, colors, and ornaments. The quality of the parchment directly influenced the beauty of the final manuscript, with the finest and whitest (vellum) being reserved for the most precious works.

Parchment was gradually replaced by paper, which was easier to produce and less expensive, from the 14th century onward, but remained for a long time the preferred support for official documents and luxury manuscripts.

Tempera Painting

Tempera painting is an ancient pictorial technique where pigments are mixed with a water-soluble binder. Unlike oil painting, it dries quickly and offers matte colors with a particular luminosity.

The fundamental principle is based on preparing a binder made from animal glue (such as rabbit skin glue), gum arabic, or egg yolk or white (tempera). This binder is then mixed with powdered pigments to create the paint.

Very popular in the Middle Ages and Renaissance, tempera was used for altarpieces, illuminated manuscripts, and frescoes. Great masters like Fra Angelico and Botticelli employed it with virtuosity before oil became predominant.

The illuminator mixed his pigment with the binder to obtain the paint, which he stored in shells.

Today, it is appreciated for its ecological qualities, its rapid drying time, and its characteristic matte finish that allows for unique transparency and layering effects.

Pigments

The main pigments and their origins

Blue pigments

• Lapis lazuli (ultramarine blue): Semi-precious stone imported from Afghanistan. Extremely expensive, reserved for the most prestigious manuscripts.

• Azurite: Copper mineral less costly than lapis, extracted from European mines. Lighter blue and less stable.

• Indigo: Organic pigment derived from plants (Indigofera tinctoria), imported from India and later cultivated in Europe.

Red pigments

• Vermillion (cinnabar): Mercury sulfide of mineral origin, very vivid and opaque.

• Minium: Orange-red lead oxide, artificially produced, used for capital letters (hence the term “miniature”).

• Kermes and cochineal: Organic colorants derived from insects, producing bright reds.

• Madder: Plant pigment extracted from the roots of the Rubia tinctorum plant.

Green pigments

• Verdigris: Copper acetate obtained by exposing copper to vinegar vapors.

• Malachite: Copper carbonate mineral with intense green color.

• Iris green: Juice extracted from iris or other plants mixed with alum.

Yellow and brown pigments

• Orpiment: Arsenic ore with brilliant yellow color, highly toxic.

• Ochres: Natural earths rich in iron oxides.

• Saffron: Expensive spice derived from the stigmas of Crocus sativus.

White and black pigments

• Lead white: Lead carbonate prepared by exposing the metal to vinegar vapors.

• Carbon black: Derived from the combustion of wood or bones.

• Lamp black: Soot collected after burning resins or oils.

Preparation and use

The pigments were carefully ground on porphyry or marble stone, then mixed with binder (egg white). The illuminator organized his palette according to a symbolic and economic hierarchy. Precious colors (ultramarine blue, vermillion, gold) were reserved for important elements of the manuscript, while less expensive pigments were used for backgrounds and secondary details.

Pigments were not only chosen for their beauty, but also for their symbolism: lapis blue evoked the sky and the Virgin Mary, vermillion red signified Christ’s passion, gold represented divine light.

Gilding

Leaf Gilding

This is the most prestigious technique, giving an incomparable brilliance to luxury manuscripts. Its process involves several delicate steps:

1. Preparation of the ground: A layer of special adhesive (often Armenian bole, red clay mixed with glue) is applied to the areas intended to receive the gold.

2. Application of the leaf: Gold beaten into extremely thin leaves is delicately placed on the ground that has been moistened by breathing on it.

3. Burnishing: After drying, the gilded surface is polished with an agate stone or a wolf or ox tooth to obtain a bright and reflective appearance.

Mixtion Gilding

This is a simpler but less spectacular technique where an oily adhesive (the mixtion) is applied to the surface to be gilded. This method offers a matte appearance, often used to contrast with burnished areas.

Shell Gold

Simpler but less brilliant, this technique uses gold ground into fine powder: the gold powder is mixed with a binder such as gum arabic or egg white. This mixture is applied with a brush like ordinary paint. This method was particularly used for fine details and highlights.

Gilding does not only have an aesthetic function: it has a symbolic and spiritual dimension, with the light reflected by the gold evoking the divine presence in religious manuscripts. The quality of the gilding also marked the social status of the manuscript’s patron.

Book Trades in the Middle Ages

In the Middle Ages, besides the illuminator we have already discussed, the production of a manuscript involved several specialized craftsmen, each intervening according to a precise operational chain:

The Parchment Maker

Responsible for manufacturing the writing support, he transformed animal skins into parchment through a complex process of soaking, hair removal, stretching and sanding. The quality of his work determined that of the entire manuscript.

The Copyist or Scribe

He transcribed texts with rigorous calligraphic mastery. The copyist ruled the pages and reserved spaces for illuminations. The rubricator was a specialist in titles and subtitles; he inscribed in red ink (hence his name) the chapter beginnings, titles and liturgical indications of religious texts.

The Bookbinder

Working at the end of the chain, he assembled the quires, sewed the cords and created the cover, often in leather over wooden boards for precious works.

The Bookseller

He is the ancestor of the publisher. He coordinated the work of the different craftsmen, managing orders from wealthy clients: nobles, ecclesiastics or rich bourgeois.

Professional Organization

From the 13th century onwards, with the development of universities and the secularization of book production, these trades organized themselves into guilds in major university cities such as Paris, Bologna or Oxford. Craftsmen often worked grouped together in specific neighborhoods, near universities or cathedrals. The apprenticeship system was rigorous: several years with a master before being able to practice independently.

This division of labor, combined with meticulous transmission of know-how, enabled the creation of illuminated masterpieces that today constitute invaluable testimony to medieval art.

Glossary

Colophon

Final note in a manuscript often mentioning the name of the copyist and illuminator.

Codex

In antiquity and the Middle Ages, a set of written sheets sewn together and bound, ancestor of the modern book (hence, codicology : the science that applies to the study of manuscripts)

Drôleries

Small humorous or fantastical marginal scenes adorning the borders of manuscripts.

Incipit

First words of a text, often richly decorated in manuscripts.

Initial/Drop capital

Large decorated letter marking the beginning of a text or paragraph. Historiated initial: describes an initial or border decorated with figurative scenes illustrating the text.

Miniature

Small-scale painting illustrating a manuscript (from Latin “minium”, red lead oxide).

Vellum

High-quality parchment made from the skin of stillborn or very young calves.

Pouncing pattern

Perforated drawing allowing the transfer of a motif by dabbing.

Ruling

Set of lines drawn on parchment to guide writing.

Rinceaux

Decorative motifs in the form of coiled plant stems.