Painting on wood panels:
advantages and features

Wood panels served as the primary painting medium for centuries, long before canvas became the dominant medium in artists’ studios. This traditional medium has undergone a long evolution — from the Byzantine icons of the 5th and 6th centuries preserved in St. Catherine’s Monastery to modern experiments with acrylic paints and mixed media. Wooden supports continue to attract artists with their unique physical properties and potential for artistic expression.

Historical development of technology

Painting on wood reached its peak in Italian art from the 13th to 16th centuries, before canvas became widespread. The Byzantine icon painting tradition laid the foundations for working with wood supports, using encaustic and tempera. Renaissance masters perfected the technology of panel preparation, developing complex multi-layer priming systems.

The choice of wood was determined by the workshop’s geographic location and the availability of materials. In the Netherlands and Flanders, Baltic oak ) Quercus spp.) was preferred, supplied via the Hanseatic League’s trade routes. A study of 294 panels by Jacob Jordaens and Anthony van Dyck revealed that over 71% of the panels originated in the Baltic region, and 20% came from western Central Europe. Italian artists more often used poplar, which grew locally and had suitable characteristics for painting.

Panel-making technology was passed down through guilds. Boards were carefully dried, often curing the wood for years before use. For larger pieces, multiple planks were glued together with animal glue or a casein-lime mixture. Radial sawing helped minimize warping. Wooden slats, strips, and mechanical devices were used to connect multiple boards and prevent significant warping.

Surface preparation system

The process of priming the wooden base was labor-intensive and multi-step. The dried and sanded wood was first coated with a sizing layer — a hot 5% solution of animal glue made from hides. This layer served as an insulator between the wood and the subsequent layers. A thin fabric — linen or cotton (pavoloka) — was glued to the sizing layer to prevent the sizing layer from cracking as the wood moved.

Once dry, numerous layers of gesso — a mixture of powdered gypsum and animal skin glue — were applied. The traditional technique involved two stages: first, two layers of liquid gesso ("milk"), then 8 to 10 layers of a thicker mixture. Each layer was sanded before the next, alternating brushstrokes to ensure even coverage. The panel was then sanded and polished to an ivory-like smoothness. This perfectly smooth surface allowed for detailed work with thin layers of paint.

Early panel paintings typically had integrated frames — the panels were glued into the frames before subsequent layers of glue and primer were applied. When such works were removed from their frames, the exposed wood remained visible along the edges.

Materials and their properties

Types of wood

The choice of wood species influences the durability of the piece and the behavior of the base over time. Oak, particularly Baltic oak, was prized for its density, stability, and straight grain. Dendrochronological analysis allows for the dating of panels and the determination of the wood’s geographic origin with high accuracy. Poplar ) Populus spp.) was widely used in Italy due to its softness, ease of workability, and availability.

Contemporary artists use birch plywood, marine plywood, basswood, and maple. Birch provides a smooth surface and stability. Maple is considered ideal for staining due to its uniform grain. MDF (medium-density fiberboard) offers an economical alternative with a smooth surface, although it requires careful sealing due to its porosity.

The density and texture of the wood determine how well the paint will absorb. Softwoods exhibit significant density differences between earlywood and latewood, which can create unevenness. Hardwoods provide a more consistent finish. The wood should be thoroughly dried and acclimated to workshop conditions for at least a week before preparation.

Binders

Egg tempera dominated panel painting in the early Renaissance. The pigment was mixed with egg yolk or white, producing various effects. The mixture dried quickly and created a durable coating. Manuscripts by Jean Le Bégué (1368–1457) contain instructions: the yolk was pierced with a needle, squeezed into a vessel, a drop of water was added, and the mixture was mixed with pigment. Adding oil to the tempera prevented it from drying out.

Oil paints gradually replaced tempera from the late 15th century, offering a longer working time and rich tonal transitions. Flemish masters developed sophisticated techniques of multi-layered oil painting on oak panels. Analysis of the Portuguese work compared to its Flemish counterpart revealed nearly identical pigments and layering, but differences in the composition of the ground and the use of gold leaf.

Acrylic paints have gained popularity in modern painting due to their quick drying, flexibility, and minimal toxic fumes. Water-based acrylic dispersions adhere well to primed wood. Contemporary artists often use acrylic gesso for priming, which allows for control over texture, from perfectly smooth to rough.

Advantages of wood panels

Physical stability

Wooden panels provide a rigid, non-dynamic surface that doesn’t sag or warp like stretched canvas. This stability is especially valuable for detailed work and precise techniques. The smoothness of the prepared panel surpasses the woven texture of canvas, allowing the artist to create exceptionally thin layers of paint and achieve a high degree of realism.

The hard surface is ideal for drawing with charcoal, graphite, and oil pastels. Unlike canvas, which absorbs the material due to its weave, wood retains the pigment on the surface. The panels can withstand the significant stress of mixed media — from encaustic wax to multi-layered acrylic washes.

Durability

Properly prepared wooden panels demonstrate exceptional durability. Byzantine icons from the 5th and 6th centuries have survived to this day in good condition. Compared to canvas, wood can outlast canvas for centuries. Wood is less susceptible to the tears and punctures that threaten fabric backings.

The dense structure of the wood protects against mechanical damage. The panels withstand transportation and storage better than stretched canvas. Dimensional stability, when properly sealed, prevents the formation of waves and sagging typical of aging canvas.

Texture control

Artists have extensive control over surface texture. Primer can be applied to create a perfectly smooth base or a rough, sandpaper-like surface. Canvas offers a limited selection of pre-made textures, while panel painting allows for instant adjustments to the roughness without leaving the studio.

Some contemporary artists deliberately preserve the visible structure of wood — annual rings, knots, and unique markings become part of the work. This approach transforms wood into a collaborator, adding narrative and depth. The natural beauty of the material is integrated into the artistic concept.

Structural capabilities

Wood can be shaped and carved, adding a three-dimensional aspect to a work. Panels support relief work and inlay. Medieval carved wood reliefs combined sculptural elements with painting. Contemporary artists use milling, wood burning, and other woodworking techniques to create complex multimedia works.

The panel’s rigidity allows for the application of heavy materials — thick impasto, resin, and collage elements — without the risk of warping the substrate. The flat surface ensures reliable adhesion for assemblage compositions that require stability and a non-springy canvas.

Technological difficulties

Warping and cracking

Wood is hygroscopic — it absorbs and releases moisture depending on environmental conditions. Significant thermo-hygrometric fluctuations cause changes in the wood’s structure. Panels may warp, and the gesso, which is harder than wood, can develop dangerous delaminations. Wooden panels stored in insufficient humidity often warp and crack with age.

The panels warp slightly over time because the back side is exposed wood, while the front side is protected by layers of paint and primer. It’s impossible to completely prevent some expansion and contraction; this is a natural property of the material. Attempts to completely stop this movement can cause further damage, as the panel will move against its restraints.

The recommended humidity level for panel works is 50% at a temperature of approximately 20°C. A stable and level environment with minimal fluctuations in temperature and humidity reduces risks. Conservators avoid straightening curved panels, as this can cause more damage. Instead, the work is stabilized and properly framed to reduce visual distortion and limit humidity fluctuations on the back.

Preparation and weight

Wood panels require more careful preparation than canvas. Sanding, gluing, and applying several coats of primer take considerable time. The surface must be sealed to prevent warping and paint absorption. Natural acids in wood can discolor over time, so sealing is essential.

Contemporary artists use Golden’s GAC 100, a special medium for sealing wood before priming. Acrylic gesso is applied after sealing. All surfaces — front, back, and edges — must be sealed before painting. An unbalanced seal, where only the front side is covered, allows moisture to migrate more freely to the back, leading to warping.

Weight is a significant drawback. Panels are significantly heavier than canvas, making transportation and hanging difficult. Large-format wooden works pose logistical challenges. High-quality panels are more expensive than canvas. Thick plywood, stable hardwoods like birch or maple, and engineered wood are more expensive than stretched canvas.

Conservation challenges

The conservation of panel paintings is complex and depends on the original materials and techniques used to create the support and numerous preparatory layers. The history of stress and strain to which the work has been subjected affects its state of preservation. Previous restorations may include metal clamps or other restraining elements that cause dramatic damage as the wood attempts to free itself.

Computed tomography reveals delaminations between layers, wood grain patterns, old knots, and cracks. Thermography, multispectral imaging, and macro-X-ray fluorescence spectrometry provide information about materials and execution techniques. Non-invasive methods allow conservators to plan interventions without damaging the work.

The PICUS system, developed for measuring delamination between layers of architectural coatings, has been successfully tested to obtain information about the execution technique, state of preservation, and previous interventions in stratified panel structures. Deformation monitoring includes linear potentiometric sensors, strainmeter kits, fiber Bragg sensors for localized measurements, and full-field methods such as digital image correlation, stereo correlation, marker tracking, 3D modeling, and moiré.

Modern practice

Acrylic paints on wood

Acrylic paints have become the dominant medium for modern wood panel painting. Water-based acrylic paints offer excellent weather resistance, although they are characterized by brittleness, insufficient adhesion, and poor water resistance. Composite modification systems based on alkyd resins improve the adhesion, water resistance, and elasticity of acrylic films.

Cellulose nanocrystals are showing promising results as an additive to biological water-based acrylic wood coatings. Self-healing UV-curable acrylate coatings are being developed for wood floors where high abrasion and scratch resistance are required.

The technique for preparing a panel for acrylic painting involves sealing it with GAC 100 and applying several layers of acrylic gesso, sanding between coats. Artists often tint the panel before beginning work. The panel’s hard, smooth surface is ideal for acrylic painting, allowing precise brushstroke control without the paint soaking into the texture.

Comparison with canvas

Canvas dominates contemporary practice due to its lightness, flexibility, and portability. Its stretchable nature makes it ideal for large formats. It’s easier to handle, transport, and hang. Canvas is more accessible and easier to prepare. Artists working with expressive techniques and dynamic brushstrokes prefer the pliability of canvas.

Wood excels where precise control is required for detailed work. The panels do not require re-stretching and do not sag over time. The lack of a fabric texture allows for exceptionally smooth transitions. For work with heavy materials, mixed media, and three-dimensional elements, wood provides a more reliable base.

The choice between panel and canvas is determined by artistic goals, the scale of the work, budget, and logistics. Some artists alternate between supports depending on the project. Panels are particularly attractive for realism, botanical illustration, miniatures, and graphic work that values precision. Canvas remains preferred for abstract expressionism, large-scale compositions, and works requiring transportation.

Experimental approaches

Contemporary artists explore wood not just as a paint carrier, but as a material with its own expressiveness. Structured light, shearography, and thermography are used to examine historical panels and also inspire artists to take new approaches to surface treatment. Plasma treatment of wood modified with hot oil reduces the discoloration of the acrylic coating during natural weathering.

Photo transfer, impasto, stenciling, sponging, and drybrush techniques expand the possibilities. Combining wood with rubber, plastic, photography, and textiles creates multimedia works. Wood burning, milling, and inlay add a sculptural dimension.

Artists experiment with various wood species, preserving or emphasizing the natural qualities of the material. Chestnut, ash, and cherry offer distinctive textures and colors. Oriented strand boards made from poplar are vacuum-treated, altering their color and wettability. Composite impregnation with a silica and melamine-glyoxal resin solution modifies poplar wood, improving its physical and mechanical properties.

Specifics of different genres

Icon painting

The Byzantine iconographic tradition established the canons for working with wooden supports. Encaustic painting — painting with molten wax paints — was used in early icons but gradually gave way to tempera. The gesso was made from gypsum and animal glue and applied in multiple layers. The red bolus beneath the gold leaf was identified using infrared spectroscopy.

An 1836 decree regulated icon-painting techniques. A multidisciplinary approach — infrared thermography, multispectral imaging, and macro-X-ray fluorescence spectrometry — allows for the study of icons without damage. Mapping the distribution of chemical elements reveals the materials and techniques used.

Chinese architectural painting

Ancient Chinese architectural painting on wood surfaces demonstrates unique techniques. A study of the painting materials on the Dazhong Gate of the Confucius Temple in Qufu, Shandong Province, revealed the use of protein glue as a binder. The detection of boiled tung oil by pyrolysis gas chromatography-mass spectrometry indicates a connection with traditional Chinese wood painting techniques.

Consolidating materials for color paintings on ancient wooden architecture require careful evaluation. Various compounds are tested for compatibility with the original materials. Conservation of such works takes into account the specific climatic conditions and cultural context.

Flemish School

Flemish masters of the 17th century developed a highly developed system of panel painting. Dendroprovenance analysis of paintings by Jacob Jordaens and Anthony van Dyck reveals an active Baltic timber trade and the use of Western European sources. Interestingly, panels from the Baltic and the Ardennes region (France/Belgium) were used together in three different works, likely cut from larger panels.

Marking and branding oak panels was a common practice in the centers of art production in the Southern Netherlands, such as Antwerp, in the 16th and 17th centuries. A study of a panel maker who branded his pieces with a house mark of two letters "M" stacked on top of each other, topped with the number "4," identified his clients among artists active between 1632 and 1648. A dendrochronological study of eight of the twenty-three known panels, combined with art historical research, suggests that the workshop was located in Rotterdam.

X-ray computed tomography allows for non-invasive dendrochronology, revealing hidden features. A study of a work attributed to Rubens’ workshop revealed a double panel: the back (visible) panel of deciduous oak was dated terminus post quem to after 1557, while the front (original) panel was identified as a tropical wood, likely Swietenia sp., rarely used in Netherlandish painting. The presence of exotic wood demonstrates the global nature of 17th-century trade and the use of exotic species in Flemish workshops.

Renaissance techniques

Italian Renaissance craftsmen developed sophisticated methods for constructing wooden bases. Techniques varied depending on the period, region, type of work, and artist. Nails were oval or rectangular in cross-section, tapering from large, thin, round heads to pointed tips. They were hammered into partially pre-drilled holes and bent back into the wood in a U-shape to ensure optimal resistance to pull-out. The spacing between the nails was regular and carefully planned.

Egg tempera served as the primary technique for applying paint to panels during the early Renaissance. Mixing it with egg yolk or egg white produced various effects. The mixture dried quickly and was durable. A typical wood panel was prepared by coating the surface with layers of gesso (gypsum mixed with animal glue and ground to a thick paste). A rough coat was applied, followed by thinner layers, with sanding in between.

Michele di Matteo’s "Coronation of the Virgin" (first half of the 15th century) demonstrates the technique of the late Gothic Italian painter. Spectroscopic analysis revealed imprimatura with lead white and a gypsum-based ground layer. Pigments, possibly applied with an egg binder, correspond to the period of the work’s creation. Modern pigments used in subsequent restorations were also discovered.

The wooden panels served not only as a base for painting but also as a source of information about trade routes, workshops, and technologies. Baltic oak traveled from the Baltic ports to Antwerp via the Hanseatic League trade routes before being delivered to the artist’s workshop. Many manufacturing marks and assembly techniques clearly correspond to those found on other panels by the artist, demonstrating the workshop’s practices.