INTERPRETING ARTIST'S INTENT IN THE TREATMENT OF JOHN CONSTABLE'S THE WHITE HORSE SKETCH
Because the overpaint was so heavy, it was not possible to ascertain the precise condition of the original painting prior to its removal. However, some clues were provided early in the cleaning that gave hope for a good result. The painting was covered not only with heavy, opaque repaint, but with a thick layer of markedly discolored varnish. Since it was a relatively simple task to remove this coating from the overpaint without affecting it, the varnish layer was removed first. The painting became brighter, but it did not appear technically any more like a painting by Constable. However, removing this varnish fortuitously revealed two areas where previous attempts at cleaning the painting had removed the overpaint layer to reveal what was beneath it. One area, in the upper right corner, showed the feathery, active brushwork of a Constable sketch in the clear, bright color that this area of the sky in the Frick version also displayed. Although this triangular area measured only 3 × 3 in., the exposed original paint seemed remarkably well preserved. The second area was in the center of the sky above the cottage. It was known from notes in the National Gallery conservation files that a cleaning test had been performed in 1946. The conservator, apparently not understanding that he had removed overpaint, abandoned the notion of continuing the cleaning because “the paint was easily soluble and appeared to be painted in a varnish medium.” His test, though a little overzealous, also showed the expected tones in a well-preserved, sketchy style. Encouraged by these two glimpses of the painting beneath the overpaint, proceeding with the cleaning was not as daunting.
Painstakingly, the repaint was removed using organic solvents and the aid of a binocular microscope, one square inch at a time, over several years (1992–97, not working every day). To universal delight, a stunning, fresh, lively, and well-preserved fully realized sketch for the Frick painting was revealed (fig. 8, p. 366).
The White Horse, after conservation treatment