One of the issues that challenge collectors, dealers, and curators alike is how to authenticate a work of art that is not signed by the artist and for which there is no documentation. The portrait shown in figure 1 originally presented just such a challenge. Stylistically it has all the hallmarks of a pastel by John Singleton Copley (1738–1815), who created about fifty-five portraits in this medium between 1758 and when he departed for Europe in 1774; the vast majority of his sitters were Boston residents. For Copley, this was an easy medium in which to work and, as it placed little demand for repeated sittings, won favor with his clients.
