Watercolor is a painting technique making use of water-soluble pigments that are either transparent or opaque and are formulated with gum to bond the pigment to the paper. Although the grounds used in watercolor painting are varied, the most common is paper. Others include papyrus, bark papers, plastics, leather, fabric, wood, and canvas.
History of Watercolor
Watercolor techniques started evolving with the invention of paper by the Chinese shortly after 100 AD. Papermaking was introduced to Spain by the conquering Moors in the 12th century and spread to Italy decades later. Some of the oldest paper manufactures include Fabriano, Italy, opened in 1276, and Arches, France, opened in 1492.
The forerunner of watercolor painting was buon fresco painting: wall-painting using watercolor paints on wet plaster. Probably the most famous example of buon fresco is the Sistine Chapel, begun in 1508 and completed in 1514.
The earliest known use of this technique was by the Italian Renaissance painter Raffaello Santi (1483-1520), who painted some full-scale cartoons as precursors for some tapestry designs.
In Germany, Albrecht Dürer (1471-1528) painted in watercolor in the 15th century. The first school of watercolor painting in Europe was led by Hans Bol (1534-1593) and was much influenced by Dürer's creations.
Other famous artists have used watercolor painting to supplement their work with oil paint, including Van Dyck (1599-1641), Thomas Gainsborough (1727-1788), and John Constable (1776-1837).
In 18th century Britain Paul Sandby (1725-1809) was called the father of British watercolor.
Someone having better knowledge of art has to write about watercolor evolution after the 18th century
The broader term for water-based painting media is "watermedia". The term "watercolor" still seems most often to refer to traditional transparent watercolor or to gouache, an opaque form of the same paint. These are specific types of watermedia.
Watercolor paint is made of pigment mixed with gum arabic for body and glycerin or honey for viscosity. Gouache has an added content of unpigmented filler to lend opacity to the paint and oil of clove to prevent mold.
Traditionally, watercolor is applied with brushes, but it may be mixed with other materials (usually acrylic or collage) and applied with other implements in experimental approaches. According to a tradition dating from at least the early 20th Century, the white of the paper is the only white used in transparent watercolor. The paint is thinned when applied to allow for lighter passages within the painting. Opaque paint is seldom used for whites or to "overpaint". This lack of opacity provides watercolor its peculiar characteristics of brightness, "sparkle", freshness, and clarity of color, since the light from a watercolor has passed through the film of paint and is reflected back to us through the film.
Watercolor techniques have the reputation of being quite demanding, although in reality they are not more demanding than those used with other mediums. Maintaining a high quality of value differences and color clarity are typically the most difficult qualities to achieve and maintain.
The medium is equally effective in portraiture, figurative art, photorealism, and abstract work, both objective and non-objective. (Kandinsky produced the first non-objective abstract paintings in transparent watercolor around 1913). Watercolor is prized by its proponents as a studio medium for its lack of smell and ease of cleanup and also as a plein air medium for its portability and quick drying.
Fingerpainting originated in China with watercolor paint.