Joseph Mallord William Turner

A mid-blue coloured wash was applied over the whole of this white sheet of paper before painting. Bower suggests1 that the fairly straight boundaries to the wash at right and left imply that the sheet was stretched on a board. This would have been done with gummed tape, which at this time might have been home-made by Turner or his father, who acted as his studio assistant. Thoroughly wetting a sheet of paper lying on a board can be sufficient to hold it in place: it is not necessary to tape it down on all four sides. Indeed, rather few sheets in the Turner Bequest provide evidence for any taping, though trimming would have destroyed the evidence in many cases. Turner on occasion glued down paper to a board, which was a faster and more convenient method than making gummed tape, soaking it, letting it dry before working on the paper, and eventually painting it with water to free the sheet. This practice of gluing down paper is known because his one surviving board is in fact the reverse side of the unfinished oil George IV’s Departure from the ‘Royal George’, 1822 (Tate N02880), painted c.1822 on a substantial, thick hardwood panel just large enough for the purpose at 752 x 921 mm yet small enough to carry around the studio easily. This bears evidence of several sheets having been stuck down successively, probably loosened with a knife at one corner, then impatiently ripped off by Turner, leaving substantial shreds of paper and many colours of watercolour wash behind, at least three sheets of paper deep. Not all the sheets are the same size: it is more likely he used the board sporadically than that he turned it into the equivalent of a large-scale sketching block by sticking down many sheets for use one after another.

Bower further notes that Turner’s intense working of the paper to different degrees left different amounts of glue size on the surface, which in turn affects the sharpness of outline of the last wash applied. He suggests that here Turner used glue size for the stopping-out method which in other cases would also have worked using gum water. The method involves painting on a detail with glue size, and letting it dry. Watercolour wash on top does not take well to the sized area, in the same way that the first brush-load of watercolour paint applied to glue-sized paper wets out less than the later brushstrokes. Gum water stopping-out is partly removed by later painting, and can always be cleared away with cold water. Glue size requires hot water for removal. This means that more working can be done over it, in the sure knowledge that it will not destroy the intended precise effect of the stopping-out. The hard-edged white patches of cloud in the sky illustrate this effect.