To cover lighty, as a painting, or a drawing, with a thin wash of opaque colour, or with colour-crayon dust rubbed on with the stump, or to make any similar additions to the work, so as to produce a softened effect. (The Online Plain Text English Dictionary) There are two senses for this term. Its earlier meaning: a broken passage of opaque or translucent colour (often paint) skimmed or dragged across the surface in such a way that each color is visible, each modifying the other, or, to apply a colour in this way. This technique was developed by the Venetian school of painters (chief among whom was Titian, c. 1488 - 1576), who passed dry, opaque coats of oil paint over a tinted background to create subtle tones and shadows. Although this painting technique dates to the 16th century, use of the word "scumble" in order to refer to it is unknown before the late 18th century. The origins of the word "scumble" are blurry [!], but the word is thought to be related to the verb "scum," an obsolete form of "skim" (meaning "to pass lightly over"). A later sense for scumble: to smudge or smear the lines, edges, or colours in an image by rubbing lightly. This use appeared in the mid-1800s. (

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