‘John Johnstone, Betty Johnstone, and Miss Wedderburn’, ca. 1790/1795, National Gallery of Art, Washington, D.C.
overall: 101.5 x 120 cm (39 15/16 x 47 1/4 in.)  framed: 119.4 x 138.4 x 6.4 cm (47 x 54 1/2 x 2 1/2 in.)