The importance of tonal values in landscape art

Why tone does the heavy lifting

Tone — the relative lightness or darkness of a shape — is what tells the eye where to look and how far to travel. A distant hill reads as distant because its values are lighter and softer than the dark hedge in the foreground, not because it happens to be a different colour. Turn a favourite landscape painting to greyscale and you will usually find a clear, simple structure underneath: a few distinct blocks of value sitting in a sensible order. Turn a weak painting to greyscale and everything collapses into a similar soup.

This matters more in Britain than many painters admit. Our weather gives us soft, wraparound light, long tonal gradients and plenty of grey. Without deliberate value contrast, a Welsh valley or a Norfolk marsh can end up looking like a rainy Tuesday no matter how bright your greens and ochres are.

Learning to see value rather than colour

Most beginners paint what they know is there rather than what they see. Grass is green, so it gets painted green, and the value gets whatever is left over. Add the way a camera flattens contrast and the way a screen lies about shadows, and you can spend hours painting a scene whose structure you never actually observed.

Two habits fix this quickly:

• Squint. Half-close your eyes until detail disappears. What is left are the big value shapes. Squinting is the fastest filter you own, and it works in the field as well as in the studio.
• Match against a scale. Make a five-step grey scale — white, light grey, mid grey, dark grey, near-black — from a scrap of card and a couple of marker pens. Hold it up against the landscape and decide which step the field sits on, which step the trees sit on, which step the sky sits on. You will often be surprised by how dark foliage and how light wet tarmac really are.

Plan light, middle and dark before you paint

A useful discipline is the three-value study, sometimes called a notan: a small sketch made with only three tones. Light, middle, dark. Not five. Three. The restriction forces decisions. You have to choose whether the cottage wall belongs with the sky or with the road, and whether the trees group together as one dark mass or separate into individuals.

Work at postcard size, no bigger than 12 x 16 cm, with a chisel-tip marker, a stick of charcoal or a flat brush loaded with Payne's grey. Aim to finish each study in five to ten minutes. Do four or five versions of the same view, pushing different shapes darker or lighter each time, then ask which one best expresses the light you remember. That question — which arrangement feels most like that place at that hour — is the whole job.

What a grey-scale study should tell you

A good study answers practical questions before you mix a single colour:

• Where is the light coming from? The brightest light shape is the companion to your focal point, and it should sit near the area of strongest contrast.
• What is the darkest dark? In most landscapes it is a foreground shadow, a doorway or a dark tree line, and it should be used sparingly. One or two darks carry the whole picture.
• How much of the picture is middle value? Usually most of it. Too many competing lights and darks make a restless painting; a generous middle lets the extremes sing.
• Does the value pattern lead the eye? Follow the sequence of light and dark shapes as if walking through the scene. If your eye stops dead in a corner, adjust the study rather than the painting.

Tonal mistakes that flatten a landscape

Certain errors show up again and again. Painting darks too light is the most common: hedges, shadowed walls and distant woods end up as mid-tones, and the picture loses its spine. The opposite problem is over-darkening everything, which produces a heavy, muddy result and kills aerial perspective. Distance generally means less contrast, lighter darks and softer edges, while the foreground can hold your strongest value jumps.

Another trap is confusing colour contrast with value contrast. A bright red against a deep green feels lively, but if both sit at the same value the painting still looks flat. Test colour mixtures on a scrap of board and check them against your grey scale before they go anywhere near the canvas.

Carrying tone into colour

Once the value plan works, colour becomes easier and far more expressive. Decide your overall key first — a high-key painting of a hazy summer morning, or a low-key one of a storm over the Pennines — then keep your mixtures inside the corresponding range. Hold the intended value and you can choose almost any hue: a dark tree mass can be olive, violet or near-black blue and still read correctly. Break the value and no amount of clever colour will save it.

Keep a small sketchbook of grey studies alongside your colour work. Sketch outdoors whenever the light is doing something interesting, and note the time on each page. Over a season you will build a personal library of tonal structures, and you will find that planning light, middle and dark shapes takes minutes but transforms everything that follows.