Capturing the texture of bark and foliage

Why bark and foliage resist tidy marks

If you have ever painted a tree trunk with a single flat stroke of brown, you will know the disappointment. Bark is not a smooth cylinder. It is a record of weather, growth and damage: vertical fissures, horizontal plates, peeling strips, patches of moss and lichen. Foliage is not a green cloud either. It is a mass of individual leaves, twigs and gaps, catching light in unpredictable ways. The moment you try to render either with neat, even marks, the painting looks plastic. The solution is not more detail but better mark-making. You need to suggest roughness with dry brush, sponging and layered marks, and you need to vary pressure and direction so your hand does not fall into a repetitive rhythm.

Dry brush: dragging colour across the grain

Dry brush is your first tool for bark. Load a hog bristle or stiff synthetic brush with thick, undiluted paint, then wipe most of it off on a rag or newspaper. The brush should feel almost dry. Hold it at a low angle to the paper or canvas and drag it lightly across the surface. Because there is little moisture, the paint catches only the top of the texture, leaving the paper's tooth to show through. That broken, scratchy line is exactly what bark looks like.

For a vertical fissure, use a flat brush and pull downwards with a slight zigzag. Press harder at the start of the stroke and ease off at the end, so the mark tapers. For horizontal plates, as on birch, turn the brush on its side and pull short dashes, varying the length and the gap between them. Do not make every mark the same length. Some should be long and thin, others short and blunt. If you are painting oak, build up three or four layers of dry brush in different browns and greys, each time changing the angle slightly. The ridges between the marks become the bark's texture.

Sponging for lichen, moss and leaf masses

A natural sea sponge is perfect for the soft, mottled surfaces of lichen and moss. Tear it into irregular pieces rather than cutting it, so the edges are ragged. Load the sponge with two or three colours at once — perhaps a yellow-green and a grey-green — by dabbing it into the paint and then working it on a palette until the colours are partly mixed but still distinct. Dab lightly on the paper, twisting your wrist as you go. For moss on a trunk, sponge over a dry-brushed bark base. For foliage masses, use the sponge to block in the main clumps of leaves. Do not cover the whole area. Leave gaps for sky or background to show through, because those gaps are what make the foliage read as leaves rather than a flat shape.

Layered marks: building from mid-tone to detail

Texture is built in layers. Start with a mid-tone shape, perhaps a flat wash of grey-green for a tree's canopy or a warm brown for a trunk. Once that is dry, add darks with a rigger or small round brush. Twigs and deep bark crevices are best drawn with thin, slightly wobbly lines. Do not draw every twig. Suggest a few, then let the viewer's eye fill in the rest. Next, add lights with dry brush or a sponge. A pale grey or ochre dragged lightly over the high points of the bark will make it pop. Finally, scumble a transparent layer of colour over the whole area to unify the marks. Each layer should use a different tool and a different direction. That variety is what keeps the surface alive.

Vary pressure and direction to break repetition

The biggest enemy of natural texture is repetition. If every stroke is the same length, same pressure and same angle, the painting looks mechanical. Train yourself to change something with every mark. Rotate the brush in your fingers between strokes. Pull one mark downwards, the next sideways, the next diagonally. Use your whole arm, not just your wrist, so the marks have a different character. Press hard for a dark, heavy mark; barely touch the surface for a whisper of colour. Try using your non-dominant hand for a few marks — they will be awkward and unpredictable, which is exactly what you want. Step back from the painting every few minutes and look at it from a distance. If a patch looks like a pattern, break it up with a sponge or a dry brush stroke in a new direction.

Taking it outdoors: quick studies and a simple kit

Outdoor sketching is the best way to learn texture because you see how light actually catches bark and leaves. Keep your kit light: a sketchbook with textured paper, three brushes (a flat hog, a rigger, a fan or old brush for dry brush), a small natural sponge, a water pot, a rag, and a limited palette of earth colours plus a couple of greens. Work in twenty-minute studies. Choose one tree or one bush and focus only on its texture. Start with a mid-tone wash, then dry brush the trunk, sponge the foliage, and add a few dark twigs. Do not try to finish it. The aim is to capture the feel of the surface, not a botanical illustration. Overcast days are wonderful for texture because the light is soft and revealing. Sunny days give you strong shadows, which help you see the direction of the bark's ridges. Finish the study at home if you like, but keep the original energy. The best texture comes from confident, varied marks, not from fiddling.