In the 18th cent. the modern aquarelle grew from the simple wash coloring of a drawing into a technique of complete painting. This technique became particularly popular in England, where its greatest masters were Constable and J. M. W. Turner. Rowlandson, Cozens, Girtin, Bonington, Cotman, and John and Paul Nash were also celebrated for their use of the technique. Many 19th-century painters also used watercolor extensively, mostly for landscape paintings and sometimes for portraits, but it was no longer commonly used for miniatures. The French artists Daumier, Delacroix, and Géricault, and later, Cézanne, Signac, and Dufy, employed aquarelle to a large extent, for both preliminary sketches and finished works. The American John Singer Sargent became well known for his aquarelles. Other painters in the United States, including Homer, Whistler, Prendergast, Marin, and Sheeler, painted noteworthy watercolors.

The advantages of watercolor lie in the ease and quickness of its application, in the transparent effects achievable, in the brilliance of its colors, and in its relative cheapness. Aquarelles have a delicacy difficult to achieve in oil and are equally flexible, lending themselves to immediate expression of a visual experience. Their handling demands considerable skill as overpainting of flaws is usually impossible. Watercolor was traditionally a comparatively perishable medium, vulnerable to sunlight, dust, and contact with glass surfaces, but the use of modern pigments has made it much more stable.