Paul Sandby (1731–1809) was a landscape painter and leading practitioner of the process of aquatint used to reproduce the watercolour painting in print. He pioneered the spirit ground method, in which resin was dissolved in spirit and painted onto a warmed plate, the spirit evaporating and leaving the resin behind in the shape of the brush strokes. Sandby varied the size of resin grains he applied to the plate; the clouds, for example, are very fine grain. For the white patches, he ‘stopped out’ parts of the plate by painting in varnish to prevent the resin from touching them. This effect is best seen in the clouds and on the figures.
Aquatint is often combined with line etching since both techniques were etched and printed at the same time. This image was printed in brown ink, but parts were also hand-coloured, such as the castle windows. Under a magnifier the printed colour takes on the granular appearance of the aquatint resin grains, while hand colouring is seen as brush strokes.