Why Not Just Paint on a Table? Seeing What You Are Doing

A picture viewed at an angle is foreshortened, so working on a flat horizontal surface means judging shapes that are being seen distorted, and proportions drawn to look right on the table look wrong once the work is hung. Holding the surface upright removes that, since the artist sees the picture as a viewer eventually will. An upright surface also allows the artist to step back, which is the single most useful action in painting, since problems of proportion, tone and composition that are invisible at arm's length become obvious from three metres away. And it lets the work be placed directly beside the subject, so the eye moves between them with the least possible change of position.

Different work demands different arrangements:

• •The A-frame, three legs folding flat, cheap and adequate for small work
• •The H-frame, a rigid upright base that does not move when the brush presses
• •The single mast studio easel, which cranks the canvas up and down mechanically
• •The field easel, lightweight with a telescopic construction for outdoor work
• •The pochade box, a small case holding panel, paints and palette together
• •The table easel, for small work and for those without floor space

Painting from a portable stand in front of the subject became practical in the nineteenth century and changed what painting looked like. Before that, outdoor work was limited to sketches taken on site and worked up in a studio, and the change depended on several developments arriving together, notably paint in collapsible metal tubes from the 1840s, which replaced pigment ground fresh and stored in animal bladders, and lighter folding stands and boxes. The impressionists exploited this directly, and the qualities their painting is known for, including rapid handling, bright unmixed colour and the recording of a particular light, follow from working in front of the subject and finishing on the spot rather than from any theory.

Studio practice around the stand is more deliberate than it looks, and a few habits account for much of the difference between a working painter and a beginner. The canvas is placed so that its centre is near eye level, since working above or below that height distorts judgement of the whole. A mirror hung behind the painter lets the picture be seen reversed, which reveals errors of drawing and balance that the eye has stopped noticing through familiarity. Placing the palette beside rather than below the work keeps the colour being mixed in the same light as the colour being matched. Turning the picture upside down periodically breaks the reading of it as a subject and forces it to be seen as shapes and tones.

Working outdoors from a portable stand is less romantic than the pictures suggest. Wind is the principal enemy, since a canvas is a sail and a light stand is unstable, which is why weights are hung from the centre and why many painters have watched work blow into mud. Direct sun on the painting alters the colours being judged and produces glare, so an umbrella or shade is standard equipment. The light moves continuously, so the shadows the composition depends on shift within an hour or two, which forces a painter to establish them early and stop looking. Insects land in wet paint. And everything must be carried, which is why the equipment is so relentlessly minimised.

An upright surface removes the foreshortening that makes a flat surface misleading, allows stepping back, and lets the work sit beside the subject. Rigid studio forms differ from light portable ones by how much they move when a brush presses. Paint in metal tubes and lightweight folding stands made outdoor painting practical in the nineteenth century, and the qualities of impressionist painting follow directly from finishing on the spot.