A painting technique, impasto is a thick application of paint that does not attempt to look smooth. Instead, impasto is unabashedly proud to be textured and exists to show off brush and palette knife marks. Just think of nearly any Vincent van Gogh painting to get a good visual.
Traditionally, artists strive for clean, smooth brush strokes that are almost mirror-like. This is not the case with impasto. It is a technique that thrives on expressive textures of thick paint that pop out from the work.
Impasto is most often created with oil paints as it is one of the thickest paints available. Artists can, however, use a medium in acrylic paints to get a similar effect. The paint may be applied with a brush or a paint knife in thick globs that are spread onto the canvas or board.
Impasto painters quickly learn that the less you work the paint, the better the result. If one were to touch the paint with a brush or knife repeatedly, it works itself into the canvas, becoming duller and flatter with each stroke. Therefore, for impasto to have the greatest effect, it must be applied with deliberation.
It's easy to see the relief of impasto paint when a piece is viewed from the side. When looking straight at the piece, it will have shadows and highlights around every brush or knife stroke. The heavier the impasto is, the deeper the shadows are.
All of this creates a three-dimensional look to the painting, and it can bring a piece to life. Impasto painters enjoy giving their pieces depth, and it can add a great emphasis to the work. Impasto is often referred to as a painterly style in that it celebrates rather than downplays the medium.
Impasto is not a modern approach to painting. Art historians note that the technique was employed as early as the Renaissance and Baroque periods by artists such as Rembrandt, Titian, and Rubens. The texture helped give life to the fabrics many of their subjects wore as well as other elements in the paintings.
By the 19th century, impasto became a common technique. Painters like Van Gogh utilized it in almost every piece of work. His swirling brush strokes rely on thick paint to give them dimension and add to the expressive qualities of the work. Indeed, had a piece like "The Starry Night" (1889) been done with flat paint, it would not be the memorable piece it is.
Throughout the centuries, artists have employed impasto in many ways. Jackson Pollock (1912–1956) said, "I continue to get further away from the usual painter's tools such as easel, palette, brushes, etc. I prefer sticks, trowels, knives and dripping fluid paint or a heavy impasto with sand, broken glass or other foreign matter added."
Frank Auerbach (1931–) is another modern artist who unabashedly uses impasto in his work. Some of his abstract works such as "Head of E.O.W." (1960) is exclusively impasto with thick gobs of paint covering the entire wood support. His work brings to life the thought many have that impasto is a painter's form of sculpture.