Pastels can be traced back to the 16th century. Its invention is attributed to the German painter, Johann Thiele. A Venetian woman artist, Rosalba Carriera was the first known artist to make consistent use of pastel. Chardin did portraits with an open stroke, while LaTour preferred the blended finish. Thereafter, a galaxy of famous artists....Watteau , Copley, Delacroix, Millet, Manet, Renoir, Courbet, Toulouse-Lautrec, Whistler, Cassatt, Bonnard, Hassam, William Merritt Chase, Vuillare, .... just to list the more familiar names, used pastel in finished works rather than only preliminary sketches.
The French Impressionist, Edgar Degas was the most prolific user of pastel, and its champion. Degas eliminated most of the white addition that earlier pastel artist favored, used pastel in strong, pure colors and , allowed his individual strokes to part of the final composistion, instead of blurring them into the overall effect in a kind of imitation of light oil painting, which pastel can achieve quite easily.
Pastel is very important in the work of Mary Cassatt, as in that of Degas, her friend and mentor. The first really prominent artist to use pastel was also a woman, Rosalba Carriera, during the first half of the eighteenth century. For Carriera, as for other eighteenth and early nineteenth-century artists, pastel was a way to paint with full color on the full surface without having to wait for drying to see the final effect.