Scumble

Scumbling is a technique of applying very slender layers to the painting. It is valuable for very smooth gradations, and also for adjusting dried out layers. It can be used immensely to manipulate the reflective or absorptive light qualities inbuilt in pigments. Scumble is a technique analogous to glazing, except that the coating is opaque. It is usually quite hard to identify if a painting has been done using 'scumble' or 'glaze'.

Scumbling techniques have been utilized by painters since the 1600s to make smooth gradations, alter a previously dried layer of paint and to create a sense of depth. This technique is achieved by applying thin layers of light opaque colors over dark layers of dried transparent paint. The finishing results gives a painting a surface that differs in how much of the under painting is revealed.

The scumbling technique is frequently used to form a beam of light penetrating a usual darken room. It is also helpful to include a glowing effect to highlight individual objects and skin tones. Scumbling has a very reflective result, and is excellent for building form and depth by building the illusion that the surface is coming toward the viewer. Scumbled areas are bright at a distance.

The major advantage of scumbling is that if it does not bring out the desired effect the still wet top layer can be removed with a clean cloth alone or with a solvent like turpentine.

Famous painters and paintings that employ a scumbling technique:

Rembrandt‘s paintings called “Artist Contemplating the Bust of Homer” and “Self Portrait”.
Both of these were oil paintings on canvas.

The French Master David Jacques Louis and his painting “Madame Charles-Louis Trudaine”