Plein Air Value Studies: A Simple Field Method for Better Paintings

You set up your easel, the scene looks exactly right, and you start painting with real enthusiasm. An hour later, something has gone wrong. The painting feels muddy, the light has shifted, and what seemed so clear in front of you has become a confused mess on the board. It happens to almost everyone who paints outdoors, and it's genuinely demoralising.

The most common reason for it is straightforward: the value structure was never decided before the first brushstroke. Colour was chosen, detail was chased, and the fundamental pattern of light and dark was left to sort itself out. It rarely does. Plein air value studies solve this problem. A small tonal sketch made before you start painting gives you a clear decision about where the lights and darks go, and that decision holds the whole painting together even when the light shifts, the clouds come in, or the scene gets complicated. This article explains what a value study actually is, why it matters specifically outdoors, and gives you a step-by-step field method you can try at your next session.

What Is a Value Study (and Why Does It Matter Outdoors)?

A value study is a small, usually monochrome sketch that reduces a scene to a handful of tones. There's no colour involved, no detail, and no attempt to produce a finished image. The goal is to see the pattern of light and dark clearly so you can make a deliberate plan before committing to a full painting. Think of it as a map drawn before the journey rather than a record of it.

In a studio, you can take your time. You can return to the same setup tomorrow if you need to rethink the composition. Outdoors, that luxury doesn't exist. The light in Britain can shift from bright and raking to flat and grey in twenty minutes. A scene that looked dramatic when you arrived might look entirely different by the time you've mixed your first colour. The value study captures the essential pattern before it changes, giving you something concrete to work from even when the conditions move on.

Complex outdoor scenes compound the problem. A hedgerow full of different greens, a building with multiple shadow planes, water reflecting a partly cloudy sky: these all present an overwhelming amount of visual information. Without a tonal plan, it's easy to paint everything at equal weight and end up with a composition that has no clear focal point and no sense of light. The study forces you to simplify before that happens.

UK conditions make this particularly relevant. Overcast skies, which are the norm for much of the year, flatten tonal contrast and make it harder to see the value structure intuitively. British summer landscapes are notorious for their intensity of green, where every area reads as a variation of the same hue even when the tonal differences are significant. Low winter sun creates extreme value shifts that change rapidly as the sun moves. A few minutes spent on a thumbnail study before you start is genuinely useful in all of these conditions.

Values, Tone, and the Squint Test

The difference between value and colour

Value is how light or dark something is, entirely separate from its hue. A deep red and a deep green can share the same value. A pale yellow and a pale blue can share the same value. When you convert a colour photograph to greyscale, every colour that looked distinct suddenly reveals whether it was actually contributing a different tone or just a different hue at the same tonal level.

This distinction matters enormously outdoors. Beginners often think in terms of colour when they should be thinking in terms of tone. When you're standing in front of a British summer landscape, you're looking at an enormous range of greens: yellow-greens in the sunlit grass, blue-greens in the distant trees, dark bottle-greens in the hedgerows. The colour differences are real. But the tonal differences within that green scene are equally real and far more important for the structure of your painting. Two areas that look different because of their colour might be contributing the same tonal mass, and treating them as the same value is often the right call compositionally.

How squinting helps you see value

Squinting is the single most useful free tool available to any outdoor painter. When you narrow your eyes significantly, colour information is suppressed and the main light and dark masses become visible as large shapes. Detail disappears, subtle hue variations disappear, and what remains is the basic tonal pattern.

Practise this before you touch your sketchbook. Squint at the scene until you can see just two or three large masses. Note where the lightest area is, where the darkest area is, and roughly where a middle tone sits. That's the information your value study needs.

If squinting alone isn't enough, particularly on days when the scene is very complex or the light is very flat, try the phone photo method. Take a quick reference shot on your phone and convert it to greyscale. Most phones allow this directly in the photo editing tools. The resulting image shows you the tonal structure of the scene without the distraction of colour. On a grey overcast day in a British valley, where everything can look like a variation of the same cool mid-tone, the greyscale image will often reveal significant value differences that your colour-trained eye was suppressing.

The Three-Value System: A Practical Field Method

For most plein air planning, three values are all you need: light, mid, and dark. This is the recommended default, particularly if you're new to doing thumbnail value studies. It's simple enough to work quickly in the field and thorough enough to give your painting a genuine structural foundation.

Why three values and not more

Using too many tones is one of the most common mistakes in a planning study. Five or six values sound more precise, but in practice they create more decisions, more opportunities for confusion, and a final painting that looks tonally muddy and indecisive. The strength of the three-value approach is that it forces you to commit. Every shape in the scene has to go into one of three buckets. That decision-making pressure is the point: it's exactly the kind of simplification your painting needs.

If a composition works clearly in three values, the underlying design is sound. If it doesn't work in three values, adding more tones won't fix it. It will just obscure the problem.

A simple three-value painting exercise before you set up your easel takes five minutes and will save you from an hour of confusion in the actual painting.

Notan: the two-value version

Notan is a Japanese term for the harmony of light and dark. In practice, the notan approach means reducing everything to two values only: pure black and pure white. There's no mid tone at all. The purpose is to check whether the composition reads as a clear, distinct pattern of light and dark shapes.

It's a useful first check. If the two-value version looks confused or ambiguous, the composition probably needs rethinking before you go further. Some painters do a quick notan sketch before moving to a three-value study. Others go straight to three values. It's not essential, but the term comes up regularly in plein air circles and it helps to know what it refers to.

How to Do a Plein Air Value Study: A Step-by-Step Field Method

Some painters worry that doing a thumbnail study before painting feels mechanical, or that it removes the spontaneity that makes outdoor painting worthwhile. It's a reasonable instinct, but it's worth turning around: the study is what enables the painting to be spontaneous. Once the fundamental light and dark decisions are made, you can paint with confidence and freedom rather than second-guessing every mark. The plan is what makes the spontaneity possible.

Before you commit to one thumbnail, do two or three variations. Try placing the dominant dark mass in a different position. Try a version where light dominates and another where dark does. The light is changing while you work, and a few minutes spent exploring alternatives at thumbnail stage is far more productive than realising halfway through a full painting that the composition isn't working. Getting this right at thumbnail stage takes minutes, not an hour.

Gear for Value Studies in the Field

You don't need specialist equipment for plein air value studies. The simplest possible kit is genuinely enough.

What you actually need:

• A small sketchbook, A6 or A5. Anything larger makes it harder to fill quickly with small thumbnails
• A dark pen, fineliner, or marker for the darks and outlines
• A mid-grey marker or diluted ink wash to indicate mid tones
• Alternatively, a compact watercolour set with a single neutral dark pigment: Payne's Grey or Lamp Black work well

Jackson's Art, Ken Bromley, and Cass Art all stock compact sketching kits that are well suited to this kind of work. You don't need anything specific to value studies; if you have a basic sketching kit, it will do the job.

Common Value Study Mistakes (and How to Fix Them)

"I can't see the values in a green UK landscape": This is very common, particularly in summer when British countryside is an intense wall of green. Squint until the colour disappears and only the light and dark masses remain. If squinting isn't enough, photograph the scene and switch it to greyscale on your phone. If two areas look the same value in greyscale, they are the same value, regardless of their colour. Trust the greyscale image over your instinct.

"My study looks fine but my painting still went wrong": You probably abandoned the value structure once colour came into the mix. It happens constantly. The moment you pick up a brush loaded with colour, the thumbnail can get forgotten. Keep the study visible while you paint and refer back to it regularly. The value map in your thumbnail is only useful if you actually use it. If the colour in your painting is drifting toward a different tonal pattern, stop and look at the thumbnail again before going further.

Putting Value Studies Into Your Outdoor Practice

Experienced UK plein air painters use thumbnail value studies habitually, not just on difficult days or unfamiliar locations. It becomes a natural part of arriving at a spot: look at the scene, squint, do a couple of small thumbnails, then set up the easel. The whole process takes five to ten minutes and changes the quality of what follows significantly.

You don't need a full day out to practise this. A thirty-minute lunch break in a local park is enough to do two or three thumbnail studies without touching any paint at all. That kind of regular, low-pressure practice builds the skill quickly. The eye genuinely improves with repetition, and keeping your studies in a dedicated sketchbook lets you see that improvement over time.

If you'd like to see how other UK painters approach this, groups like British Plein Air Painters and London Plein Air Painters (which has over 300 members) are active communities where you can observe and discuss working methods. Events like Paint Out in Norfolk bring together painters at all levels working outdoors together. These aren't just social occasions; watching how other painters plan and simplify a scene is one of the fastest ways to develop your own approach. Structured tuition is also available through venues like the St Ives School of Painting and the Art Academy London for those who want guided practice.

Whether you're working alone in the countryside or at a group event, the principle is the same. Spend five minutes on a thumbnail before you start. Block the darks in as flat shapes, add the mid tones, leave the light. Check the pattern reads clearly. Then paint from that plan.

The study takes five minutes. The improvement it produces doesn't take much longer to notice.