Dripping and splattering paint was a favored technique of Jackson Pollock.
Painting techniques have changed over the years from delicate glazes to direct painting. Watercolor, oil and acrylic paints share some techniques but have a few that are exclusive to the medium. Though it may not appear so when a work is complete, it is common for an artist to use more than one technique on a single canvas.
Watercolor Techniques
One watercolor technique, hard and soft edges, involves the heavy application of paint on dry watercolor paper with one brush. A second brush loaded only with water is touched to the edge of the heavy paint, causing gradient color. Both hard and soft edges are created with the second brush. Paint applied to dry paper ensures the strokes will stay where they are placed. This is a dry brush technique. Wetting the paper before applying paints, called painting wet on wet, assists the artist in blending paints. The paper is tilted to allow the paint to flow over the surface rather than seep into a single spot. In negative painting, the focal point of the piece is left unpainted and darker areas are filled in.
Oil Painting Techniques
Direct painting begins with a drawing done in charcoal, pencil or thinned paint. Broad background areas are filled in with blocks of color. As the artist continues, detail is built up using fatter paint, which is paint that has a higher oil content. The application of finer details with soft brushes follows. Early Flemish painters developed the technique of painting in layers. Beginning with an accurate drawing, layer upon layer of thin washes and layers of glaze are added. As each layer is completed, the canvas is left to dry. The completed canvas is a glowing and translucent image. Painting on a toned background, a classical approach, begins with coating the canvas with a thin dark tone of paint and then drawing on top of the dry canvas. Shadows are rendered with raw umber or another earth color, filling in areas to be built up with more color. The artist adds more definition and light while making use of the dark tones of the canvas.
Acrylic Painting Techniques
Acrylic paints have their own peculiar techniques, though there are similarities between oil and acrylic paints. A flat paint technique involves layering enough paint on the support to create a flat-looking surface devoid of tonal change. Light and dark shades of hues are laid on top of an under-painting. This creates light and shadow and a three-dimensional appearance.
Oil over Acrylic
Oil and acrylic paints cannot be mixed but they can be layered. The under painting is executed in shades of white and black acrylic. The artist must take care to keep his acrylic layer thin, producing an image similar to a black and white photograph. Oil paints are then added in colored glazes. The benefit of this method over using oil paint for the under-painting is time. An acrylic under-painting will dry within hours of completion so that glazing can begin immediately.
Scrapping and Rubbing
Scraping and rubbing are used with all three mediums. Once the paints are built up in an area where the artist wishes to let lower levels show through, the paint is scrubbed or rubbed. Any tool can be used; steel wool, metal spatulas and keys will all cut through the top surface of the paint. It is possible with acrylic paints, because of their plastic quality, to peel away strips of color. Pigments in both oil and watercolor paints can be rubbed away using solvent or water on a brush, paper towel or rag, provided the oil has not completely hardened.
