How to prepare the board for the icon? The technological process.
Two types of wood are used for the icon – softwood ( linden wood) and hardwood, such as oak or ash. Linden wood is taken from th forest, where the rivalry of trees forces the linden tree to grow quickly upwards and the straight, knot-free trunks grow. Natural linden boards 4-5 cm thick are seasoned for at least 5 – 7 years (il. 1). During this time, the tree dries naturally. Its flexibility and healthy structure are preserved. The wood is not dried out and too dead, has no micro-cracks or other defects that may occur in dried wood using the accelerated method. Hardwood is felled from specific batches of wood in order to avoid blemishes and to choose the right grain direction (il. 2)(il. 3). The elements from which the icon will be made are selected from uncontaminated parts of the board – i.e. those that have no knots, are healthy throughout their thickness and do not and will not have cracks. The core (earlywood) is also omitted because it is of too low quality. After cutting and pre-forming the boards, they are glued (il. 4). Flat surfaces should be glued together. Although such a joint is slightly weaker than on a toothed surface, it has greater resistance to cracking right next to the face, where the forces caused by the chalk-glue primer (levkas) are formed. The boards are also not randomly arranged. As far as possible, they are arranged alternately, so that the natural deformations tolerate each other, maintaining the flat character of the painting (il. 5).
After being glued together (il. 6) the boards are cut to the required format and polished (il. 7). The next step is to cut down the wood for wedges (il. 8). Wedges are transverse beams that stop the board from deforming. Deformation may cause cracks in the chalk-glue soil (levkas) and together with it the painted surface. Wood is a material susceptible to humidity and temperature, which brings with it undesirable deformations. However, the skilful selection of wood and the use of wedges will significantly extend the time during which the painting remains flat. The cutout is wedge-shaped (il. 9). The cut-out angle is repeated on the wedge and fits perfectly (il. 10). The wedges must not be glued, nailed or fixed in any other way. Permanent fixing of the wedge has the opposite effect to the desired one. The board may become bulging or even crack under the generated pressure.
The wedge is made of hardwood. It is selected from completely defect-free elements (il. 11). It is cut so that its fibres are placed at right angles to the linden wood (il. 12). This is an ideal situation, not always applied in practice. It ensures the rigidity of the clutch, which makes it impossible to deform.
Then the boards are carved (il. 13). The relief is sometimes extended and sometimes ends with a deepened front. After the relief has been finely finished, the boards are glued with hot rabbit glue. The warmer the glue, the deeper the wood penetrates. However, the glue must not overheat or boil as it loses its qualities. After gluing the board should dry completely (il. 14). The carved board is then covered with fabric. It can be linen, cotton or other fabric of natural origin. The fabric allows the primer to penetrate the wood, but at the same time prevents the transfer of microcracks from the face of the board to the face of the primer and paint (il. 15). Such cracks occur over time and in a natural way. They cannot be completely avoided with wooden paintings. The goal of the covering of the board with fabric – just as with wedges and skilful positioning of the boards – is to avoid any damage to the painting. With more complicated reliefs, gluing is a time-consuming process. However, medieval polychrome sculptures tested in time, are visual evidence of the effectiveness of such technology. The glued and well-dried board is ready to be applied from a few to several layers of chalk-glue primer, in Europe called il gesso (il. 16) (il. 17). The number of layers depends on individual needs. Usually it is 5 – 12 layers. Tradition dictates the application of twelve layers. However, this principle is rather related to religious symbolism and is not an important technological requirement. Applying too much primer sometimes results in the erasure of the more subtle sculptural parts, which are lost in this way. The edges of the fabric are wrapped back or sheared at the edges (il. 18). This depends on the aesthetic need. It is better to leave them wrapped as this helps to keep the edges even and additionally protects against damage that may cause primer crumbling. Avoid placing the boards on hard uneven floors and be careful of impacts.
In traditional painting, the levkas is only the primer. However, in my sacral abstractions it is often an important element of painting because of its velvety and natural, self-sufficient as an artistic entity and giving organicity to the whole work (il. 19). It can be coloured, engraved, polished or shaped at the stage of laying. It is the ideal (until recently the only) surface for making high shine gold plating.