With the acceptance of Christianity in 988, Old Russia absorbed not only the theological concept of the icon, but also the technology of its embodiment in paint. Painting with colors prepared with egg yolk is one of the most ancient techniques: it was widely employed in ancient Egypt, for instance, where egg tempera was used to decorate sarcophagi.

The creation of an icon began with the preparation of the foundations beneath the painting. Usually the icon panel was assembled from one or more panels of well-dried wood, prepared with an axe. According to the rules, they used the wood of lime trees, rarely pines, and even more rarely spruce panels. If the older icons of the 12th to 15th centuries were mostly painted on linden panels regardless of their place of origin, then in the later 17th to 19th centuries it is not unusual to find woods such as alder, poplar, juniper and spruce used. Wood was prepared in the winter at times of severe frost, when it contained the least moisture. The tree trunk was split into panels with the help of an axe and wedges, removing the external, soft layer of wood (sapwood), and was dried out over a period of several years. This way of working does not destroy the cellulose fibres which make the panels more durable and prevent decay. In rare cases panels of different species are found in a single icon, as for example in the 13th-century royal gates from the Assumption Cathedral in Krivoe Pogost (Tretyakov Gallery, Moscow), where both lime and pine were used.

In the 12th to 15th centuries, icon panels were mounted in the Byzantine tradition by battens superimposed on the reverse side, or on the upper and lower edges of the icon, with the help of wooden or beaten iron pegs. The battens were fastened against the grain of the wood fibres, thus preventing in theory any warping of the panel. Between the horizontal battens, additional diagonal splints in the shape of the letters Z or X were often fastened. Battens superimposed on edges were decorated with red paint, which in later times led to the tradition of decorating the lower and upper edges with red margins – the so-called ‘opush’.

From the 15th century onwards Russian masters abandoned the ‘Greek’ mounting of panels, which led to stresses and cracks in the wood as a result of too rigid fastenings, and began to introduce wedge-shaped battens into grooves cut into the reverse of the icon. This tradition continues to this day, and is a characteristic feature of Russian icons influenced in the 18th and 19th centuries by Greek and Balkan masters.

With the appearance of the new method, superimposed battens were replaced with cut-in ones on most of the oldest icons. On the front of Russian icons, a depression was hollowed out for the main representation – the so called ‘kovcheg’ (ark or shrine), which was separated from the elevated margin or border by the ‘luzga’, a shallow angled edge. Without doubt,the designation of this hollowed-out surface for the holy image by the word ‘kovcheg’ also had a sacred meaning. Like Noah’s Ark, the icon, with its ark-harboured image, also bore salvation.

Only from the end of the 17th century did flat panels without depressions begin to be prepared, in the manner of European paintings on canvas. The defects of the panel, joins and the surface for the main depiction were covered with pieces of old, washed-out linen cloth. This ensured that the base coat adhered better to the surface of the panel. Painters to Мthis day call the base coat or primer (gesso) by the old word ‘levkas’, which derives from the name of the Greek island of Lefkas, from whence came chalk of the very best quality. Incidentally, the Russian name for the material ‘ mel’ (calcium carbonate, chalk) – itself comes from the name of another Greek island – Melos. ‘Levkas’ or gesso for icons was made from chalk, a mixture of gypsum and chalk, or gypsum alone. The powder was mixed with animal hide glue according to an ancient Byzantine recipe. Only from the end of the 17th century onwards do Russian sources begin to recommend fish glue, made from the dried bladder of the sturgeon.

In antiquity fish glue was called ‘karluk’ after the tribe which dwelt in the lower Volga region around the Caspian Sea. Onto a meticulously, but not excessively, polished primer ‘levkas’, the drawing was plotted in black paint by brush or transferred by tracing. The surface of old icons was always a little uneven, in order to create a play of light. Then the painter proceeded to gild the halos and backgrounds. Very thin leaves of gold were laid on the ochre-stained, translucent surface with the aid of animal glue, garlic juice and, later, the so-called ‘poliment’, prepared according to a Greek recipe. ‘Poliment’ consisted of processed egg white, beeswax, soap and bole – red Armenian clay. Along with gold they often used silver, and on a few old icons we even see tin. So as not to lose the contours of the representations during the gilding process, the lines of the drawing were scratched out with a needle.

Paints, even today, are prepared by mixing pigments with a water-based emulsion made from egg yolk. Egg-yolk tempera was well-known from ancient times. Paints made from egg yolks, through polymerization of the egg oils, become very solid, are not soluble, and their colors do not change. When in the 1900s the bright colors of old Russian icons were first revealed from beneath the many layers of dark lacquer and over-painting, a few Russian newspapers suggested that the restorers might be fooling the public and showing new icons in place of the old.

Since old icon painters used natural materials, their palette was limited to a few colors. On an icon one can rarely detect more than five or six pigments, usually of mineral origin. The Russian painters’ favorite colors included bright red cinnabar, white lead, lapis lazuli, ochre and orpiment, and also earth greens, malachite and black charcoal. They also used a few organic colors: cochineal, indigo. On top of the layers of tempera, paint and gold, translucent glazed colors were laid, prepared with linseed oil and lacquer varnishes.

Painting techniques became particularly complex in the 17th century, when iconographers strove to create intricate artistic effects. Egg tempera paints become matt and bleached out after drying. In order to give them clarity and shine, the icon is saturated with oil – heated linseed oil with a type of mastic (the gum of pistachio wood) or with amber, that is oil-based varnish. In the northern climate the oil quickly darkened and became almost opaque.

In the 19th century, when there were still practically no restored icons, there arose a myth deriving from one of the greatest historians of his time, F.I. Buslaev (1818–97), suggesting that the dark appearance of the Russian icon explained the naivety and lack of sophistication of the people. Today the Russian icon has become the property of world culture and it is recognized that its artistic language gave great impetus to the development of the Russian avant-garde at the beginning of the 20th century. Features of the icon such as flatness, elements of reverse perspective, withdrawing a representation from three-dimensional space and assigning to it the character of ‘a thing in itself’, the localization of color, linearity, the speculative nature of scale, multilayered symbolism and assigning meaning to all representation – all of these were, it seems, revealed only in the art of the cubists and artists of the avant-garde. In reality, these time-honored artistic devices were cultivated in the art of iconography in order to clarify in visual forms the beauty and wisdom of divine creation.

The icon always attracts afresh, because it bears within itself something eternal and unchanging. One may unreservedly apply to the icon the words of St John Chrysostom in the New Testament Epistles of the Apostle Paul: "In reading, as if in a meadow, I see a multitude of flowers, of abundant roses, violets and lilies, everywhere diverse fruits of the spirit and great fragrance".

Dr. Yury Bobrov Academy of Arts, St Petersburg May 2008 Translated from the Russian by Stella Rock