Thinned paint is applied as a transparent wash that allows the surface and/or previous layers of paint to show through. Transparent washes/glazing can accentuate the texture of the panel or canvas as pigment either pools in depressions or is absorbed unevenly. With watercolor washes, the pigment will tend to migrate to the edges of each wash area, intensifying the pigmentation of the edges. Artists can vary the amount of pigment in each wash, using more or less thinner/medium in order to increase or decrease the transparency.
Featured: The Barbed Noose with the Mice by Paul Klee.