A plain‑language glossary for the techniques you’ll meet in our posts. Think of it as a pocket dictionary for your eyes, written by a curator who likes metaphors as much as medium.
Use it while you read the blog, before a museum visit, or when you’re simply wondering what on earth a conservator means by “scumbling”.
Photo by irene mckay on Unsplash
Chiaroscuro
What it means: Strong contrasts of light and dark used to model volume and drama.
What to look for: Faces or hands emerging from deep shadow; a beam of light that feels almost theatrical; backgrounds that dissolve into darkness.
Why it matters: Chiaroscuro doesn’t just describe volume; it suggests moral or emotional contrast—light as revelation, darkness as uncertainty. Think Caravaggio or Rembrandt, or visit a post like my look at Caravaggio’s calling of Saint Matthew on the blog.
Glazing
What it means: Thin, translucent layers of oil paint applied over a dry layer so that light passes through and bounces back from the lower colors.
What to look for: Subtle color depth—skin that seems to glow from within; shadows that are not just “black” but made of greens, blues, or reds stacked over each other.
Why it matters: Glazing lets artists adjust mood and color harmony without repainting the whole form. Old Master flesh tones, polished armour, and autumn skies often rely on it.
Sfumato
What it means: Smoky, soft transitions without hard edges—literally “turned to smoke”. Associated above all with Leonardo da Vinci.
What to look for: Cheeks, chins, and backgrounds that seem to blur gently into the air; no visible outline around the nose or jaw; shadows like breath on glass.
Why it matters: Sfumato creates a sense of psychological depth. Characters feel as if they are thinking, not posing. Leonardo’s Mona Lisa is the textbook example; you can see the full painting on the Glossary of Art Techniques featured image.
Impasto
What it means: Thick, tactile paint that stands up from the surface and catches the light.
What to look for: Ridges you could almost run a fingertip along (please don’t); highlights that glitter because they are physically higher; swirling strokes in skies, hair, or foliage.
Why it matters: Impasto makes brushwork part of the subject. In Van Gogh’s Wheat Field with Cypresses, which I discuss in a Technique Tuesday post, the sky’s movement is literally built into the paint.
Underdrawing
What it means: The initial sketch on the prepared surface (ground) before paint is applied.
What to look for: You may glimpse underdrawing where paint has become transparent or along edges; in museums, infrared reflectography images often reveal dramatically different earlier ideas.
Why it matters: Underdrawing lets you watch the artist thinking—changing hand positions, moving a figure, altering architecture. It’s the ghost of indecision, and a reminder that masterpieces begin as messy drafts.
Ground / Gesso
What it means: The prepared surface—often a white or tinted layer—that covers the raw canvas, panel, or wall and receives the paint.
What to look for: In older paintings, a warm or cool ground can peek through tiny gaps in the upper paint layer, influencing the overall tone. In modern works, artists sometimes leave patches of ground intentionally visible.
Why it matters: The color and absorbency of the ground affect everything above it: how quickly paint dries, how luminous glazes appear, and whether the whole painting feels warm, cool, or neutral at a glance.
Scumbling
What it means: A broken, semi‑opaque layer of paint lightly dragged over a dry layer so that bits of the lower color show through.
What to look for: Hazy veils of color; rough, slightly chalky passages; a sense of atmosphere created not by smooth blending but by broken texture.
Why it matters: Scumbling is wonderful for mist, clouds, worn stone, and atmospheric distance. It can soften a scene without losing energy, a very different effect from the smoked glass of sfumato.
Grisaille
What it means: Painting in shades of grey (or a very limited palette) to imitate sculpture or to act as an underpainting.
What to look for: Figures that look like stone reliefs; monochrome panels on the outside of altarpieces; or a greyed‑out first layer visible under later color.
Why it matters: Grisaille helps an artist solve value (light/dark) problems before introducing color. In conservation and technical art history, identifying a grisaille layer can explain why later colors sit so convincingly in space.
Pentimento
What it means: A visible change made by the artist, where an earlier version of a form shows through with age or cleaning.
What to look for: Faint extra fingers, shifted hat brims, moved shoulders; a ghostly outline around a hand or object that no longer exists in the “final” image.
Why it matters: Pentimenti (plural) prove that a painting is not a fixed idea but a negotiation. They also help date works, attribute them to a particular hand, and separate original decisions from later retouching.
How to use this glossary
- Keep it open while you read How to Read a Painting (in 7 Steps) and try matching each step to one or two techniques.
- When you meet a technical term in a blog post, pause, look it up here, then return to the painting armed with a sharper eye.
- Before a museum visit, skim this page and pick one technique to “hunt for” in the galleries—impasto in a Van Gogh, glazing in a Vermeer, scumbling in a Turner.
For free, high‑quality images you can zoom into while you practice, visit Open‑Access Museums: Where to Find Free, Legal Images. Pair a museum site, this glossary, and the seven‑step reading guide, and you have a complete little toolset for looking.