Icons are written by an old classical technology using natural materials.
As a base there is used a lime tree board, strengthened from the other side by oak shavings. The board is veneered by a natural adhesive, then a flax fabric is glued to it, and there are several layers of glue - chalk foundation applied. Afterwards the surface is smoothed carefully, and the required parts are gilded with a thin layer of gold. The basic drawing is done by brush (smeared charcoal with water) directly on the prepared foundation on the board. It is then elaborated in a greater detail by Indian ink. For the very painting, natural pigments mixed with egg emulsion are used. The icon is then lacquered by lacquer based on flax oil, or by lacquer with an admixture of bee wax.
This technique has been used since the very beginnings of "iconography" (if we omit the first icons written by encaustic). In various countries the technique differs only in details, depending on the tradition and availability of materials used.