sfumato: soft smoky transitions without visible outlines

Learn to blend tones so forms turn without outlines: thin shadows, side-by-side tints, soft blending, glazes, and which edges to keep, studied from five paintings.

7 min read

Sfumato is the practice of letting one tone pass into the next so that no drawn line marks where a form ends. The form is carried by gradual shifts of value and temperature, and the eye supplies the edge. The word is Italian, from sfumare, to shade off or vanish like smoke, and it is tied above all to Leonardo da Vinci, who advised painting shadows and lights so that they blend "without lines or borders, in the manner of smoke." Leonardo got the effect with many very thin, translucent layers over a carefully modelled underpainting, so it is a glazing technique as much as a blending one. The method rests on three habits: keep the shadows thin and clean, set neighbouring tints side by side before you soften them, and decide in advance which few edges you will keep sharp. The manuals in our library do not use the word, so the steps below are drawn from their general advice on soft modelling and from the records of the example paintings.

What you need

Soft charcoal, a paper stump or a piece of cotton cloth, and bread or a rubber eraser for the charcoal warm-up [1]
Charcoal paper with some tooth, so the paper tone shows between the particles of black [1]
A primed panel or canvas for the oil exercise
Oil colours matching the records of the example paintings: titanium white, yellow ochre, burnt umber, burnt sienna, cadmium red light, ultramarine, and a little ivory black
Soft, clean brushes in several sizes, plus one that stays dry and clean for blending
A small amount of painting medium for thin, transparent layers

Step by step

Practise the transition in charcoal first. Cover the paper with a loose tone of soft charcoal and pass a stump or cloth lightly over it. Do not grind the black into the paper, or the tone turns opaque and smoky [1]. The same text asks you to learn to feel outlines without drawing them [1]. Sketch the darks over the middle gray, then lift the lights with bread or a rubber, so the shape appears from tone alone [1].
Model the form in white and grey before colour. One Dutch panel discussed by Solomon is fully modelled in white and grey and then thinly coloured, with parts such as the chin and neck barely touched [2]. Build the whole value structure this way, with no outline, so that every turn of the form is already settled when colour arrives.
Paint the shadows thinly and keep white out of them. The advice attributed to Rubens is to start the shadows thinly and not let white creep in, because white dulls the transparency and warmth of a shadow and leaves the colour heavy and grey [3]. Mix shadows from earths and blue, as in the warm, transparent shadows recorded on Raphael's faces and drapery.
Load the lights and lay the tints in place. In the lights the paint may be fuller, but each tint goes down in its own place with the next tint beside it [3]. Do not mix them on the palette into one average. The softness comes later and should not be built into the mixture.
Blend lightly where tints meet. Rubens's maxim is that the tints are softened by a slight blending with the brush, passing one into the other without stirring them [3]. Use the dry, clean brush with barely any pressure, working across the join and not along it. Stop when the join disappears. More blending only muddies the colour [3].
Melt the shadow edge into the light. Solomon credits the roundness and fleshiness of Velazquez's "Dwarf" largely to edges of shadow that melt into the lights, and he describes the surface as homogeneous and soft [4]. On a face, aim for the result recorded in Winterhalter's "The Spring", where no line separates the nose from the cheek. Move the shadow into the light by small steps of value, and let each step overlap the last.
Finish the transitions with thin glazes. The skin in Bouguereau's "Lady Maxwell" is recorded as built up in thin glazes, with imperceptible transitions. Raphael's soft edges where skin meets fabric are likewise recorded as the product of transparent glazing and careful blending. Let the blended layer dry, then glaze over it with thin, warm colour to unify the passage.
Keep some edges hard. Solomon criticises a head whose edges are too clearly cut and not lost and found enough against a dark background [5]. The reverse also applies. Raphael's drapery silhouettes stay sharp while the transitions inside the shadows are feathered, and Winterhalter keeps the bouquet crisper than the face. Choose the one or two edges that carry the focal point and leave the rest soft.
Squint to check. Squinting shows whether the values hold together as a few clear zones. In the example records the face is the lightest area and the background is the darkest, with a narrow middle band between them. If the zones fall apart when you squint, the fault is in the values, and more blending will not fix it.

Common mistakes

Adding white to the shadows. It makes them chalky and heavy and takes away the glow [3].
Grinding the charcoal in your warm-up. You get an opaque, smoky tone with no light left in it [1].
Stirring tints together. Overworking the join mixes the two colours into mud. The tints should pass into one another and not be churned [3].
Softening every edge equally. Solomon's complaint about a "hard tinniness" comes from edges that are all cut the same way, and an image with every edge soft has the opposite problem, with nothing lost and found [5].
Using thin, dark background paint against flesh. In one Terburg portrait the background tones blacken the flesh because the thin pigment cannot resist the dulling action [2]. Keep the background and the flesh in separate, clearly judged layers.
Drawing the outline first and blending to hide it. The charcoal exercise teaches you to feel outlines without drawing them [1]. Model the turn of the form and let the edge fall out of it.
Blending the whole canvas to the same softness. Raphael's architecture is recorded with crisper, more visible strokes than his figures, which helps the figures advance. Bouguereau handles his dress more loosely than his skin.

Study these paintings

the-holy-family-by-raphael: Look at where skin meets fabric. The record describes nearly imperceptible edges produced by glazing and blending, with shadows that stay warm and transparent and are not black. Compare the feathered transitions inside the drapery shadows with the sharp silhouette edges, and compare both with the crisper brushwork of the architecture.

venetian-woman-at-her-toilette-by-wilhelm-marstrand: The face and the nearly black background are separated by a soft, feathered transition, and the boundary is almost imperceptible, with individual hairs losing definition into the dark. The record notes that the gradations on the cheek and forehead are extremely subtle, moving from highlight to shadow with no harsh separations. The hair carries the most visible brushwork, so you can see how much structure survives in a passage that is still seamlessly blended.

lady-maxwell-by-william-adolphe-bouguereau: The face melts into the background with no hard line, and the skin is built from thin glazes. The drapery is handled with fluent, directional strokes that follow the fall of the fabric and do not outline it, and the fur stole shows more decisive individual dark strokes. Notice how the three zones of dark, mid and bright stay clear while the edges stay soft.

the-spring-by-franz-xaver-winterhalter: The face is the record's clearest case of edges that have no line between nose and cheek, made by careful blending and glazing. The white garment shows directional strokes that follow the folds, and the bouquet in the hand is crisper than the face. Look at how the shadows melt into the surrounding tones while the folds that catch light stay gestural.

st-john-the-baptist-by-leonardo-da-vinci: Start here if you want the word in its original sense. The record describes blending that is absolute and nearly invisible throughout the flesh, with no edge between any form and its shadow, only gradation. Squint and the picture reads in three values: the near-black surround, the mid-tone body and hair, and the lit face, hand and arm. The luminosity comes from how much lighter the warm ochre flesh is than the darkness around it, not from bright whites. The hair is where the brushwork shows most, with curved strokes following the spiral of the curls, so compare it with the face to see how much structure survives inside a passage that still has no hard edge.