The practice of thumbnails

Thumbnails are about compositional intelligence, not about anatomy, rendering or refinement. This is the first step in creating a successful painting.

The goals of the exercise

The first goal is to train the eye to see structure, not objects such as trees, boats, faces, details, or buildings. Rather, it is about seeing value masses, directional flows, shape relations and visual hierarchies. It is also to ask and respond to questions such as:

• Where is the dominant value?
• Where does the eye enter?
• Where does it rest?
• Where does it exit?
• Is the composition stable or tense?

The second goal is to build compositional speed. Practice composing 5-10 thumbnails in an hour, allowing for variations, without getting attached to any one solution. Compare the solutions side by side by testing them against the question from style.

The third goal is to develop confidence in choosing representation, horizontal or vertical, large or small sky, or off-center focal points, high contrast or low contrast, calm or dramatic rhythm.

The fourth goal is to train to compose for value and simplicity, focusing on light, mid, and dark tones while avoiding fragmentation.

The fifth goal is to develop natural tendencies in composition, including diagonals, strong horizontals, central tension, large negative spaces, and a compressed value range. Does the perspective of the composition make visual sense?

Usefulness in selecting the focal area

The thumbnails should alternate between dominant and supporting shapes, adding tonal hierarchy and layering (foreground, midground, and background) to highlight a single emotional intention per design. This allows the choice among various moods conveyed by the compositions, such as calm, lonely, heroic, vast, intimate, and oppressive, early in the painting process.

Use 4B pencils to establish value in composition. Hue would add an extra layer of complexity that prevents exploration.

Incorporate value studies

Value studies are thinking exercises that reduce a subject to four values, focusing on large masses (not objects) and often ignoring texture, edges, and small shapes.

Determine big value relationships. Important focal points are dark, light, and transitional masses, as well as the connections between them.

Determine where to control contrast. The style comes to light in areas where contrast is emphasized or withheld. This can make a painting calmer or more dramatic, and it conveys the artist’s feeling.

Determine the light logic with one clear light direction and supporting shadows.

A good starting point for understanding the usefulness of Value studies in the preparation of a painting is Carlson’s theory of angles. The theory organizes the cityscape or landscape into planes based on the angle at which light strikes its component surfaces. At this stage, we need to simplify by viewing planes without micro-deviations, which will later be represented by texture. We also simplify the set of values to four values:

1. Lightest
2. Quarter
3. Half
4. Darkest

Depending on the time of day, the angle of the light hitting various planes changes. At noon, the distribution of values is shown in the image below

Value	Carlson’s Landscape plane	Cityscape equivalent	Value behaviour in Cityscape
1	The Sky	The Sky	Lightest value. It remains the primary overhead source of illumination.
2	The Ground Plane	Streets, Sidewalks, Plazas	Quarter value. Flat asphalt or concrete faces directly up to the sky, catching maximum light.
3	Slanted Planes	Roofs, Awnings, Ramps	Half value. Slanted roofs receive less light than street but more than vertical walls.
4	Upright Planes	Buildings, Facades, Walls	Darkest value. Perpendicular walls face away from the overhead sky and receive the least direct ambient light.

Specifically for Cityscape, where man-made materials abound, consider variations to the above when sketching useful thumbnails. The selection of values for planes is also conditioned by the following four factors:

1. Local Colour (Inherent Material Value): In a natural landscape, trees and soil share a relatively low, uniform local reflectivity (absorption of light). In a city, a vertical upright plane might be a gleaming white stucco wall, while the flat ground plane might be pitch-black fresh asphalt. The white wall (upright) will end up painted vastly lighter than the black street (ground), reversing Carlson’s natural hierarchy.
2. Bounced Light (Reflectivity): Nature features highly textured, light-absorbing surfaces like grass and leaves. Cities are packed with highly reflective, flat materials like glass, steel, and polished stone. Sunlight bouncing off a skyscraper window can cast intense secondary light onto a nearby vertical wall, turning a “dark upright plane” into a blazing highlight.
3. Urban Canyons (Occlusion): Tall skyscrapers block the vault of the sky. In deep streets, the ground plane can become incredibly dark because the buildings physically choke out its access to the overhead light source.
4. Artificial light sources: Street or indoor sources of light may alter the value structure that a natural one would otherwise produce.

The set of values in the thumbnail is also used to determine the best focus by identifying the area which receives the most tonal variation (three out of four) or value contrast.