modify (a painting or colour) by applying a very thin coat of opaque paint to give a softer or duller effect:the area surrounding the main figures will be scumbled
modify (a drawing) with light shading in pencil or charcoal to give a softer effect.
noun
a thin, opaque coat of paint or layer of shading applied to give a softer or duller effect.
the effect produced by scumbling.
Origin:
late 17th century (as a verb): perhaps a frequentative of the verb scum
scumble in other Oxford dictionaries
Definition of scumble in the US English dictionary
