As explained in “Time Sanctified”, Books of Hours were the bestsellers of the Middle Ages, and from the 13th to the 16 C. were produced more than any other book, including the Bible. One reason for their enormous popularity was the pictures these books contained, being the predecessors of modem book illustration.

The Book of Hours is a prayer book, however not intended for the clergy, but for ordinary people. The laiety coveted the prayers recited by the clergy, but wanted a book that was both easier to use and more pleasing to the eye. Patrons delighted in commissioning Books of Hours whose cycles reflected their devotion, their taste and their wealth. They wanted God, their friends and their descendants to recognize both their piety and good taste, so they inserted a variety of marks of ownership in various places throughout the book. The most common was to have their coat of arms painted inside the initials, along the borders of the pages, or as part of the miniatures. But the most intimate way was to have a portrait of themselves painted as being presented to the Virgin or a saint.

As in the production of modern books, there were divisions of labor which made for a smooth process. Today, one illuminator usually does all of the following work when creating a single page :

First of all the parchment from goats, calves, sheep or deer was chosen according the quality (the thinner the better) and prepared: Sanded lightly to remove the oils, then pumiced to the correct smoothness to receive ink and paint. Too much sanding or pumicing makes a suede-like surface which causes the ink or paint to bleed.

It was the scribe who commenced the work by scoring the sides of each sheet of parchment with a toothed wheel (very much like the tracing wheel used by seamstresses) to provide the preliminary marks. Then very delicate lines usually in red or brown were ruled over these marks.

Within these lines the scribe wrote his text, leaving spaces for the capital letters, miniatures and border designs. The calligraphy text was then protected from injury (from the succeeding work) by affixing a covering of old or used parchment over it.

Next the rubricator drew and painted the versals in the spaces in the text left by the scribe. Versals are the ornate capital letters at the beginning of a phrase or other important piece of text. Depending on the size of the book and the allowance of the patron, versals could range from being ornamented with color and gold leaf to one whose interior had its own miniature complementing the message of the text.

Lastly, in the production of a page, the miniaturist drew, gilded and colored the painting.

Erasures were made with bread crumbs. Today we use graphite pencils and gum (kneaded) eraser for speed and economy, as the effects of these modern tools do not appear in the finished illumination.

Old or used parchment was used to make the drawing. Then the back side was either blackened with graphite, or rubbed with Armenian bole, a hard reddish clay used to add color, but which was removable. The drawing was then transferred onto the parchment with the calligraphy and versals.

To give permanence to the transferred drawing, ink was traced over it with a goose quill pen. The ink was made either from the carbon residue inside oil-burning lamps, or from oak galls: Wasps lay their eggs in the forks of oak branches. To protect itself from “invader” the tree forms had round crusts (galls) around the eggs. These galls are crushed and mixed with water and ferrous oxide to form a very permanent ink.

Diluted ink was used for delicate linework that was to be painted in paler colors, and whole ink for outlining gilded areas, border vinework and parts of the painting requiring darker colors.

Gilding was accomplished in three ways :

1 – Raised gilding as the glue (mordant) on which the gold leaf was laid, was often gesso sottile made from white lead, slaked plaster of Paris, fish glue, and Armenian bole. Raised gilding could be burnished and tooled.

2 - In flat gilding the gold leaf was laid on a mordant of fish glue, gun ammoniac, garlic juice, hide glue, etc. Flat gilding cannot be burnished and tooled.

3 - Shell gold is gold leaf ground into a powder and mixed with gum arabic and a drop of honey. (Some illuminators claim that shell gold can be burnished ; I have found this unsuccessful, except sometimes when burnishing on paper-which I don’t use unless requested to).

After gilding came the painting. Earths, minerals, semi-precious stones, e.g. malachite or azurite, and plants and flowers were ground in a mortar and pestal to make a powder or paste, then mulled on a marble or glass plate, and finally mixed as shell gold described above. If a shinier paint was wanted, more gum arabic and honey were added proportionally. Gum arabic is brittle when dry and honey gives elasticity to the paint. Some colors are quite opaque ; some are mere glazes. Shell gold is the last color to be used as it can cover and add radiance to any other color.

These medieval techniques and materials described above are from "The Craftman’s Handbook” by Cennino Cennini written in 14th century Florence, and are the same techniques and materials that I use to create my own illuminations.