WATERCOLOUR. – A method of painting on a white or very light ground using transparent colours prepared with gum arabic and glycerine and thinned with water, so that the highlights are achieved by leaving the ground exposed or lightly veiled, without recourse to white pigments. Some artists extract the purest whites by scraping. It is advisable to preserve watercolours, since they are almost always small in size, under glass and not expose them to sunlight (see also GOUACHE).
This technique, which the Chinese used on silk as early as the 3rd century BC, has also been practised among us, especially for sketches and studies or for colouring prints and drawings. Beginning in the 18th century, in Holland, England, Italy and elsewhere, it was employed with subtle refinements by specialist artists who formed societies and organised exhibitions.
Its application in the field of sacred art is limited, though it can produce holy cards, ex-votos and small devotional images. Overbeck painted a series of Stations of the Cross in watercolour. – See Plate XXI.
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