For a portrait painter, the ability to get along with his sitters is crucial—after all, the client pays the bill—but the exercise can be wearing. Possessing a volatile disposition, Thomas Gainsborough often felt exasperated with “the nature of my damn’d business”: when an effete alderman in Bath, wearing his “five guinea new powdered bob wig,” kept insisting on being issued with a more prominent dimple, “Gainsborough burst forth in laughter, threw his pencil upon the ground, and said: ‘D—m the dimple in your chin, I can neither paint that nor your chin neither.’ ”

But others were too powerful to be handled this way: that was the case with the Earl and Countess of Dartmouth, who had insisted that Lady Dartmouth wear a classical outfit in her portrait, and Gainsborough had reluctantly gone along. Unlike Sir Joshua Reynolds, who liked to dress his women up in classical robes, Gainsborough normally preferred his in contemporary clothes.

But when the Dartmouths received their portraits, Her Ladyship was not best pleased with hers. In fact, Gainsborough had warned her that, in his view, fancy dress interfered with credibility, “the principal beauty & intention of a Portrait”: “Nothing can be more absurd than the foolish custom of painters dressing people like scaramouches, and expecting the likeness to appear.” Nonetheless, he agreed to make alterations free of charge. She still hated it. Starting all over, Gainsborough finally sent off what he had intended all along—a smaller version, but dressed “in the modern