When using oil or soft pastels, different pastel techniques produce a variety of effects. Rather than being mixed like paint, the media are primarily built up in layers. Paper selection is also important, from color to texture.
A basic method for lines and sketches is to use the end of the stick or pencil. Sharpening hard pastels and pencils produces a more precise line. A broad swath of color can be created by turning soft and oil pastels on their sides or flat edges. This is a good way to lay a foundation for adding color layers to give a picture depth.
Hatching and crosshatching are drawing and pastel techniques for blocking in a shape that use parallel lines close together. Crosshatching builds tone and shadow by adding more lines at right angles to the first. A blocked shape will usually be fine-tuned with more blending and layering. When a subject is rendered using these pastel techniques, the lines are sometimes visible.
Other artists prefer a painting’s appearance to be well-balanced. The drier media are ideal for pastel techniques that blend colors together. Color blurring can be accomplished with paper stumps, tortillons (rolled paper blending sticks), or a finger. Fingers should be cleaned frequently if they are used to avoid unintended color mixing. To provide a fresh surface, paper tools can be unrolled or peeled.
The previous pastel techniques, as well as layering colors on top of each other and letting the eye blend them, can be used to create layers. Scumbling entails dragging the pastel stick across a fixed layer of color, creating a rough texture that allows the original to show through. Feathering with fine, short strokes is another way to add texture. These pastel techniques allow viewers to see multiple colors at once and mentally mix them together.
Oil pastels employ the same pastel techniques as traditional pastels. Oil pastels have a wax and oil base rather than a chalky binder. They can be layered with an impasto look, which is a technique in which paint is applied thickly and texturedly, allowing brush or knife strokes to show through. Artists can use a palette knife or a pencil to incise oil pastels, removing layers of color to reveal others beneath. Oil pastels can also be dipped in turpentine or linseed oil to make them soft enough to spread on the painting surface.
Pastel techniques are as much about paper as they are about the medium. Paper with tooth, or a rough texture, is ideal for pastels. There’s no need for a wash with tinted paper, and different shades can bring out different colors. Oil pastels can be used on a variety of surfaces, including paper and canvas.