The technique or action of drawing a fine cloth across an inked plate in order to produce a soft smudged effect.
Origin
Mid 19th century; earliest use found in Philip Hamerton (1834–1894), artist and essayist. From French retroussage from retrousser to wipe (an etching plate) more or less clean after having inked it in such a way as to produce greater relief in certain parts of it, or to produce a smudged effect + -age.