How to Look: From Brushstroke to Craquelure

The Vocabulary of the Brushstroke: How the Paint Was Laid Down

The first language of a painted surface is the mark left by the brush. Impasto is the technique of building paint up thickly, so that the ridges and furrows traced by the brush or palette knife rise as genuine relief and, catching the gallery lights, cast their own tiny shadows. Van Gogh is the classic example; his ridges of paint only rear up like a mountain range when you look at them obliquely, from the side (many art commentaries explain that shining a *raking light* across impasto makes the surface cast its own shadows). Alla prima — also called *wet-on-wet* — finishes the work in a single pass, before the underpainting has dried, so that colors blend and bleed into one another at their edges, leaving a sense of spontaneity and speed; it is at the heart of Impressionist outdoor painting (*plein air*) — Monet, Sargent, and Van Gogh are cited as exemplary alla prima painters. Glazing, by contrast, layers transparent films of paint one over another so that light passes through the layers and reflects back from below, creating a jewel-like depth and luster (seen in the Old Masters and in some Symbolist surfaces). Scumbling is a soft, misty effect produced by lightly dragging a nearly dry, opaque brush so the color beneath shows through in patches — essentially the opposite of glazing (pulling a light, opaque color over a darker one). Broken color is the Impressionist principle of placing colors side by side in small strokes rather than mixing them on the palette, so they mix in the viewer's eye; pointillism (divisionism) systematized this into units of pure-color dots. The palette knife spreads paint with a metal blade instead of a brush, making broad flat planes or sharp ridges. Finally, look at the *direction* of the brushmarks — Van Gogh gave sky and field their motion with swirling, curving strokes that follow the grain of a form, while Cézanne built a structural rhythm across the whole picture by stacking short, parallel diagonal touches (the constructive stroke).

Media and Supports: Oil, Pastel, Gouache, Watercolor — and Canvas, Panel, Cardboard

Even when the same form is painted, the physical character of the surface changes completely from one medium to another. Oil is pigment ground into oil (usually linseed oil); because it dries slowly it can be piled up thick or layered transparently, giving it a range that runs from impasto to glazing, and it keeps a deep saturation and luster even after drying. Pastel is a dry medium of pigment compacted into sticks; the powder sits on top of the paper and scatters light, so it is velvety soft, matte, and blurred at the edges — Degas favored pastel in his later years, building depth by layering oblique, hatch-like strands of color. Gouache is an opaque watercolor that gives flat, matte planes of color and is easy to correct. Watercolor is the most luminous and transparent of all, painting thin washes of transparent color while leaving the white of the paper itself to stand for *light*. The support, too, determines the surface. Canvas is woven cloth; cast light across it and the weave of warp and weft shows up like a grid, with the canvas grain catching roughly in the brushwork. Panel (a wooden board) is hard and smooth, well suited to fine description and even glazing, and its cracking pattern runs straighter. Cardboard was a cheap support that Impressionist and Post-Impressionist painters used lightly out of doors; it is highly absorbent, so the paint sinks in and leaves a characteristically matte texture (used by Van Gogh, Toulouse-Lautrec, and others). Standing before a work, try to tell whether the surface is the grain of cloth, smooth wood, or absorbent paper/board — it lets you infer the circumstances of the artist's work (studio versus outdoors, a finished work versus a study).

Reading the Surface: The Shadow of Impasto, Varnish Gloss, Cracks, and Pentimento

The surface is a record of time and the touch of a hand. First, the shadow that impasto creates — thickly raised paint makes its own shading depending on the direction of the light, giving a three-dimensionality that a flat photograph lacks. So the same painting comes alive when the viewer steps a pace or two to the side and the glint and shade of the ridges seem to move. Second, the gloss of varnish (the protective film). A glossy varnish sinks the colors deep and glistens with reflections, so if it dazzles you head-on with the lights, step slightly aside to look. A matte or thinly finished surface (especially cardboard or Post-Impressionist works) makes the color seem to float like chalk. Third, craquelure (cracking). Over decades to centuries, an oil painting's paint layer and ground contract at different rates, and fine cracks spread across it like a net. As a rule, canvas tends toward a netted, rounded, curving pattern, while a hard panel shows straighter, more parallel cracks (differences by country/school and period have also been studied), and the direction and spacing of the cracks become clues to a work's age and the conditions in which it was kept (though they are not an absolute test for detecting forgery). Fourth, pentimento (Italian for *repentance*) — a phenomenon in which a form the artist first painted and then changed surfaces like a ghost as the paint above it gradually grows translucent with time. If the position of an arm, the outline of a hat, or an object in the background appears doubled, it may be a pentimento. Museums read such alterations and underdrawings non-destructively using X-radiography (mapping the underlying composition from the distribution of dense pigments such as lead in the paint) and infrared reflectography (making the carbon-based underdrawing visible), and they often note the results on the label or in the catalogue. In front of the real object, hunting out the traces of cracks, pentimenti, and brush corrections yourself is the most direct way to travel back through the *time of the making process*.

Color, Composition, Perspective: The Principles That Organize the Picture

Start with color. An artist sets complementaries side by side so that each lifts the other's intensity — Van Gogh made the picture vibrate with the contrasts of red-green, blue-orange, and yellow-violet. Cool colors (cold blues and greens) appear to recede and warm colors (warm reds and yellows) to advance, so color alone can produce depth of space. Try, too, to distinguish local color (an object's own inherent color) from optical/light color (the color altered by light and reflection) — the Impressionists painted shadowed snow not white but blue and violet, because they pursued not the *known* color of a thing but its *seen* color at that moment. In composition, watch for the golden section (about 1:1.618) and the rule of thirds, the steadying triangular arrangement, the diagonal that gives a sense of motion, and the *cropped frame* that boldly cuts off figures and objects at the picture's edge — under the influence of Japanese prints and photography, Degas cut figures off at the edge of the frame and left large empty spaces (negative space) to stage the spontaneity of glimpsing a scene in passing. Perspective comes in three kinds to distinguish. (1) Linear perspective: geometric depth in which parallel lines converge on a vanishing point. (2) Aerial perspective: the effect by which colors grow fainter, bluish, and hazier with distance — why Cézanne's far mountain recedes into a blue-gray. (3) Cézanne's multiple viewpoints: showing objects (road, house, field, mountain) at slightly different angles within a single picture, so that instead of the illusion of a single vanishing point the forms are *constructed* on the flat plane of the canvas (in Cézanne's Mont Sainte-Victoire the contours of foreground and background are stressed equally, so the mountain feels at once near and far). Cézanne's leaving patches of the canvas unpainted (the *passage*) or breaking contours so that planes of color flow into one another is likewise a product of this consciousness of flat structure. Every one of these devices is the trace of an artist designing not *what was seen* but *how we are made to see*.

Looking in Practice: Distance, Lighting, Frame, Label — and What a Photograph Can't Show

The last part is looking done with the body. First, change your distance. Pointillist, broken-color, and Impressionist surfaces are a disorder of color fragments up close, but step back a few paces and the colors mix in your eye (optical mixing) and integrate into form and light — so alternating between *technique up close* and *effect from afar* is the key (Seurat's Grande Jatte is the textbook of this principle). Second, step aside and look obliquely. A surface that looks flat head-on reveals, at a slanted angle, the ridges of impasto, the direction of the brushmarks, the gloss of the varnish, and the weave of the canvas — and you can dodge the glossy reflection of the lights as well. Third, be conscious of the frame and the lighting. The Impressionists sometimes preferred white or light-colored frames over the traditional gilt frame, and a frame carries the traces of the work's period, taste, and former owners (its provenance). Exhibition lighting is run, for conservation, with ultraviolet and infrared filtered out and illumination kept low (light-sensitive works such as pastels and watercolors are kept darker still), so it is normal for colors to look slightly subdued (specific color-temperature and lux figures differ from show to show, so take this as a general point). Fourth, how to read the wall label (caption): it runs in the order of artist and dates of birth/death, title (with the original title where given), date of execution, medium and support (e.g., oil on canvas), dimensions (height × width, cm), the holding institution and the circumstances of gift/purchase (e.g., Bequest of Robert H. Tannahill), and accession number — just from the medium, support, and donor information you can instantly connect the surface-reading covered above with the history of the work (part of this exhibition is from the Tannahill bequest). Fifth, deliberately seek out the things a photograph can never tell you: the real thickness of the impasto and the shadows it casts, the gloss and craquelure of the varnish, the weave of the canvas, the direction and speed of the brushmarks, the true saturation of the color (print and screen have a narrow gamut), the sense of being overwhelmed or of intimacy that the work's actual size gives, and the handling of the edges and the corners the artist left half-painted. Apply all five of these to a single painting and the same picture will look utterly different from how it did five minutes before.

At a Glance

Timeline

Glossary