Pastel does not refer to all pale colors as the word is commonly used in cosmetic and fashion terminology. Nor should it be confused with chalk. Chalk is limestone impregnated with dye.
Pastel is pure powdered pigment, the same that is used in the making of ALL fine art paint. These brilliant colors are ground into a paste with a small amount of gum binder, and then rolled into sticks. Pastel has no liquid binder that may cause other media to darken, fade, crack or blister with time. Paintings done in pastel in the 16th century exist today as fresh as the day they were painted. No restoration needed - ever!
Pastel can be used as a drawing medium or a painting medium. An artwork is created by stroking the sticks across an abrasive surface, embedding the color in the "tooth" of the sanded paper, board or canvas. Pastel can be blended, or used with visible strokes. If the ground is completely covered, that work is considered a pastel painting.
A few of the famous artists who used pastel as finished work rather than as a preliminary sketch, include: Rosalba Carriera, LaTour, Watteau, Copley, Delacroix, Millet, Manet, Renoir, Toulouse-Lautrec, Degas, Mary Cassatt, Whistler, Vuillard, Glackens and William Merritt Chase.