"Guazzo", Italian for "mud", was originally a term applied to the early 16th-century practice of applying oil paint over a tempera base, which could give a matted effect.In the 18th century in France, the term "gouache" was applied to opaque watermedia, although the technique is considerably older; it was employed as early as the 9th century in Persian miniature and had by the 14th century spread to Europe.