Byzantine icons are far more than simple devotional images; they are considered windows into the divine, theological statements rendered in wood, pigment, and gold. The techniques used to create them, refined over centuries within the Eastern Orthodox tradition, are intrinsically linked to their spiritual purpose. Central to this tradition is the use of egg tempera paint and the application of gold leaf, methods that imbue the icons with a unique luminosity and timeless quality.
Preparing the Sacred Ground: The Icon Board
The journey of an icon begins long before any paint is applied. It starts with the careful selection and preparation of a wooden panel, typically made from well-seasoned, non-resinous wood like linden, poplar, or cypress. To prevent warping, wooden slats, known as shponki, are often inserted into grooves on the back. The panel’s surface, however, is not painted directly. It must first be prepared to receive the paint and gold leaf, creating a perfectly smooth and absorbent ground.
This ground, called levkas in the Russian tradition or gesso in the West, is crucial. It typically consists of animal glue (like rabbit skin glue) mixed with a white inert powder, traditionally chalk or alabaster powder (gypsum). Multiple thin layers are painstakingly applied, often over a piece of linen cloth glued to the panel’s surface to provide further stability and prevent cracking. Each layer must dry completely before the next is applied, and the final surface is sanded and polished to an ivory-like smoothness. This flawless white ground represents the purity and potentiality of creation before the image emerges.
The preparation of the gesso ground is arguably one of the most critical stages. Any imperfections in the surface will be magnified by the subsequent layers of paint and especially by the application of gold leaf. Achieving a perfectly smooth, durable, and slightly absorbent surface is essential for the icon’s longevity and final appearance.
The Luminous Medium: Egg Tempera
Egg tempera is the soul of Byzantine icon painting. It’s a paint made by mixing finely ground natural pigments with a binder of egg yolk, sometimes thinned slightly with water or vinegar. This ancient medium predates oil painting and possesses distinct characteristics perfectly suited to the icon’s purpose.
The pigments themselves were traditionally derived from natural sources:
- Minerals (ochres, umbers, azurite, malachite)
- Earths (terre verte, sienna)
- Occasionally, semi-precious stones (lapis lazuli for brilliant blue)
These raw materials were ground into fine powders and then carefully mulled with the egg yolk emulsion on a glass or marble slab. The yolk acts as a binder, adhering the pigment particles together and to the gesso ground. It dries quickly to a hard, water-resistant film, although it remains sensitive to scratching initially.
Building Light from Darkness
Unlike oil painting where artists often work from dark to light and blend colours smoothly, traditional Byzantine egg tempera technique generally involves building up layers of light over a darker base tone. The initial drawing is transferred onto the gesso, often incised lightly. Then, a base colour, known as the proplasmos, usually a dark olive green or brown, is applied to the areas that will represent flesh (faces, hands).
Subsequent layers use progressively lighter shades of the flesh tone, mixed with more white or yellow ochre. These lighter layers, called glykasmos, are applied in fine, often cross-hatched strokes or washes, allowing the underlying darker tones to show through, creating depth and form. Highlights are added last, often with near-pure white, representing the divine light illuminating the saint from within. This method inherently symbolizes the theological concept of divine light overcoming darkness.
The colours in egg tempera have a unique depth and luminosity. The quick-drying nature forces a disciplined approach, favouring precise lines and layering over extensive blending. This contributes to the characteristic graphic clarity and spiritual intensity of Byzantine icons.
Egg tempera consists primarily of natural pigments bound with egg yolk. The yolk provides both adhesive qualities and contributes to the paint’s eventual durable, semi-matte finish. This medium requires a methodical application in thin layers and dries rapidly by evaporation.
Reflecting Eternity: The Art of Gilding
Gold leaf plays a paramount role in Byzantine iconography, symbolizing the uncreated light of God, eternity, and the divine realm. The shimmering gold background removes the figures from any specific earthly time or place, situating them in the eternal present of heaven. Applying the delicate sheets of gold leaf is a meticulous process known as gilding.
Water Gilding: The Path to Brilliance
The most traditional and brilliant method for applying gold leaf to the large background areas or halos of icons is water gilding. This technique requires the exceptionally smooth gesso ground prepared earlier.
First, several layers of a special clay mixture called bole are applied over the gesso in the areas designated for gold. Armenian bole, a fine clay rich in iron oxides, is typically used, often reddish or yellowish in colour. The bole serves several purposes: it provides a cushion for the gold leaf, allows for burnishing, and its warm colour subtly enhances the tone of the gold.
Once the bole layers are dry and polished, they are reactivated with a wetting solution, often a simple water-and-glue mixture called ‘gilder’s liquor’. A thin sheet of genuine gold leaf (often 22-24 karat) is carefully picked up using a special brush (a gilder’s tip) and laid onto the damp bole. The water tension pulls the leaf flat against the surface. Small overlaps ensure complete coverage.
After drying for several hours, the gold can be burnished. Using a polished stone tool, typically agate, the gilder rubs the surface of the gold leaf. This compresses the gold, binds it tightly to the bole, and brings it to a high, mirror-like shine. The brilliance achieved through water gilding is unmatched.
Oil Gilding: A Practical Alternative
Another method is oil gilding or mordant gilding. Here, an oil-based adhesive (the mordant), often a type of linseed oil varnish, is applied to the areas to be gilded. The mordant is allowed to dry until it reaches the correct level of tackiness – sticky enough to hold the gold leaf but not so wet that the gold sinks in and loses its shine.
Gold leaf is then applied to the tacky mordant. Oil gilding does not allow for burnishing to the same high gloss as water gilding and typically results in a more matte or subtly lustrous finish. However, it is often used for finer details, inscriptions, or assists (the fine gold lines, ‘assistes’, sometimes used on drapery) because the mordant can be painted on with precision. It’s also sometimes used for repairs or on surfaces less suited to water gilding.
Water gilding involves applying gold leaf over a layer of clay bole activated with water, allowing for high burnishing. Oil gilding uses an oil-based adhesive (mordant) to attach the leaf, resulting in a less brilliant but often more practical finish for detailed work. Both methods require skill and patience.
Finishing Touches and Enduring Tradition
Once the painting and gilding are complete, the icon is typically left to cure for a significant period – weeks, months, or even longer. This allows the egg tempera layers to fully harden. Finally, a protective varnish is applied. Traditionally, this was olifa, a boiled linseed oil varnish, sometimes mixed with amber or other resins. The olifa saturates the colours, deepens their tones, provides a uniform sheen, and protects the surface from dirt and moisture. Over centuries, olifa tends to darken significantly, contributing to the aged appearance of many historical icons.
The techniques of Byzantine icon painting – the careful preparation of the panel, the luminous layers of egg tempera built from dark to light, and the radiant application of gold leaf – are not merely technical processes. They are integral parts of a living spiritual tradition, methods developed and preserved to create images that serve as conduits for prayer and contemplation, reflecting a vision of a transfigured reality illuminated by divine light.
