A drawing or painting material consisting essentially of a stick of colour made from powdered pigments mixed with just enough resin or gum to bind them (in addition there is usually a mineral filler to give support to the fragile stick); the term is also applied to a picture produced with this medium. Pastel is applied directly to paper, with no diluent, and a significant difference between this and other methods of painting is that the colour as applied represents the final result—no allowance has to be made for changes during drying. It can produce both rich and subtle effects, with beautiful velvety textures, but it has the disadvantage of being very fragile and easily smudged or dislodged from the paper. This can be counteracted by using a fixative, but fixing can affect the colour and texture. As they are so delicate, pastels are usually used on a small scale, and they have always been especially popular for portraits. They originated at the end of the 15th century as a development of the use of chalk for drawing, and their heyday was the 18th century. The first notable artist whose career was devoted almost exclusively to the medium was the Venetian Rosalba Carriera. Her international success helped inspire the great vogue for pastel portraiture in France—Chardin, Maurice-Quentin de La Tour, Liotard, Perronneau, and Roslin being famous exponents. During the first half of the 19th century the medium declined in popularity, but it had a second great flowering in the late 19th century, especially among the French Impressionists, who found it well suited to their characteristic freshness of observation and speed of work. Cassatt, Manet, Redon, Renoir, Toulouse-Lautrec, and Whistler were all noted exponents, but the supreme master was Degas, who used pastel with a power, freedom, and inventiveness that none of his contemporaries matched. He described himself as a ‘colourist with line’, underlining the fact that pastel lies on the borderline between drawing and painting.