Gouache is an opaque water-based paint, like watercolour with chalk added, beloved by illustrators and 20th-century modernists alike.
Gouache is a water-based paint similar to watercolour but rendered opaque by the addition of white pigment or chalk. Where transparent watercolour relies on the white of the paper for its lightest values, gouache covers what lies beneath and allows the artist to work from dark to light or in any direction. The medium has been used for centuries — medieval illuminators used opaque watercolour techniques, and Persian and Mughal miniature painters worked in gouache from the 15th century onward — but the term 'gouache' became standard in 18th-century France. The Rococo painter Boucher used it; in the 19th century it became a staple of commercial illustration and design. In the 20th century, Henri Matisse turned to gouache for his late paper cut-outs ('Jazz', 1947; 'The Snail', 1953), commissioning hand-coloured sheets that he then cut and arranged. Paul Klee, Marc Chagall, and many illustrators of children's books and concept art have worked extensively in the medium. Gouache combines the immediacy of watercolour with the opacity of oil — an underrated middle path.