Pastel is essentially pure powdered pigment; the same as used in oil and watercolor paints, rolled into sticks and held together by gum tragacanth or a similar non-greasy binder. Pastels are sometimes incorrectly referred to as chalk because clay or white chalk may be added to the mixture of binder and pigment. This creates a paste, the word from which pastel got its name. Harder pastels have the addition of more paste or filler. Filler allows pastels many shades of lighter color. Black pigment is also added to some sticks of each color creating a full range of shades, from the palest to the most vivid and dark colors.
Pastel painters combine different types of pastels, using soft ones for their brilliance of hue, and hard ones for underpainting, drawing and detail. Pastel can be blended together, or left with visible strokes and lines. Generally the ground is paper, but sanded paper and boards, are also popular. An abrasive surface or "tooth" holds the pastel particles to the surface. The ground may be toned or underpainted with pastel or other water media.
If the ground is covered completely with pastel, the work is considered a pastel painting. A pastel sketch shows much of the ground. When protected by glass, pastel is the most permanent of all the mediums in existence, for it never cracks, darkens or yellows.
The medium of pastel can be used to draw and paint at the same time. There is an immediacy of translating the image directly to the working surface. One of the great joys of pastel is its textural, lively, refractive quality. Pastel has a luminous richness as light literally dances off the jewel-like multiple particles of pigment that form the surface of the painting.
Historically, pastel can be traced back to the Sixteenth Century when artists Reni, Bassano and Barocci were notable practitioners. Chardin and Quentin de La Tour made the medium equal to oil and inspired artists to take up the medium. Afterwards, a galaxy of artists, Delacroix, Millet, Manet, Renoir, Toulouse-Lautrec, Redon, Vuillard, Bonnard, Glackens, Whistler, Hassam and more used pastel as finished work, rather than for preliminary sketches. Degas was a prolific user of pastel, and its champion. His protege Mary Cassatt introduced the Impressionists to pastel. Today many of our most renowned living artists have distinguished themselves in pastels and have enriched the world with this glorious medium.