This chapter comments on the use of indigo for tinting paper in past centuries. The word indigo appears in the list of coloring materials long before its use became widespread. Ancient texts show no awareness of its diverse vegetal origin; they report the existence of a multiplicity of blue pigments, of mineral origin, such as lapis lazuli, and those containing copper, cobalt, or iron. These texts include specific advice on which painted objects the pigments will be used to best effect. Using indigo in the preparation of tinted drawing paper may have been intended as a protection against yellowing with age. Cennino Cennini and other writers are quoted regarding their recommendations on paper-dyeing techniques. The application of color washes is treated as well. In discussing the use of blue as background in 16th-and 17th-century drawings, the author speculates about the dreamy, legendary quality it imparts to them. (See also <i>AATA</i> <b>27-749</b>.)