Egyptian scribes created important historical documents using an early form of watercolor on papyrus. Widespread use of the paint didn't occur until years later during the 15th century in Europe where it was used among Renaissance painters. Early watercolor pigments were rudimentary, usually prepared by the artists themselves using their own secret recipes. It wasn't until the 18th century that William Reeves began manufacturing ready-made watercolors that could be made into sets and stored for long periods of time. Windsor & Newton later developed a tubed semi-liquid variant of the dry pigment formula in the 19th century. Further developments into the 20th century included the incorporation of synthetic ingredients that made watercolors less expensive and more vivid.
Ancient Egyptian watercolors were created using natural materials including ground stones, insect blood and fruit juices; these were then mixed with water and applied to papyrus. Renaissance era watercolors were made with more refined and highly concentrated pigments formed into large blocks. These blocks were then sold to artists in smaller portions by local art suppliers. However, artists still had to grind and mix these pigments with water prior to painting. In 1766 William Reeves began manufacturing watercolors that were instantly water-soluble by incorporating gum Arabic and honey into the production process, allowing for the pigmented blocks to attract and retain moisture.
Tubed watercolor paints were similar to those created by William Reeves but were partially moistened, which made traveling with and mixing them away from the studio more convenient. Modern watercolors are enhanced with synthesized compounds to increase the color vibrancy and adherence of the paint.
Watercolor paints are a predominantly delicate medium. Artists begin by stretching their paper so that the applied water doesn't cause it to bubble or wrinkle. Then they apply the paint, either wet-on-wet or wet-on-dry, starting with light colors and gradually building to create vibrant hues, allowing the paper to absorb the color with each application. Miskit, a gum-like blocking medium, is used to preserve areas of the paper that are to remain white or unaffected by further paint application. Salt and rubbing alcohol can also be applied to wet paint to achieve various effects.
German artist Albrecht Dürer chronicled his observations of nature through sketches created in watercolor. French Impressionist artist Paul Cézanne frequently used watercolors to paint still life compositions and "plein air" landscapes. English painter and poet William Blake illustrated metaphysical imagery using watercolors for his own published books. American painter Frank Wilcox depicted the inhabitants and scenery of his native Ohio using calligraphic watercolor techniques.