The Fine Arts Museums of San Francisco’s extensive and diverse pastel collection is the subject of the exhibition Color into Line: Pastels from the Renaissance to the Present, on view at the Legion of Honor from October 9, 2021 until February 13, 2022.
Pastel is almost pure color, composed of three elements: finely ground pigments, a dry filler (kaolin, chalk, or plaster), and a binder (traditionally a vegetable gum, such as gum arabic). When mixed with water, these elements form a “little paste” (pastello). This paste is then rolled into a cylindrical stick (the crayon) and dried. The filler gives substance to the stick, facilitating the transfer of pigment to the support, which is usually paper. There are different types of pastels. Hard pastels contain more filler and are best suited for lines, detail work, and finishing touches, while softer pastels are better at providing coverage and a velvety, pictorial finish. The concentration of the filler determines the pigment’s opacity: light hues (whites, pearl grays, pinks) are compounded with greater proportions of filler. A smaller amount of filler is used for darker and deeper tones (lampblack, Prussian blue, and indigo).