What Are Watercolor Paints Made From?

Everyone is familiar with the pan of watercolor paints in bold basic colors that preschoolers use to paint pictures. Professional artists use watercolor paints, too, and for some artists, watercolors are the only medium with which they paint.

Greg Connolly of watercolorpainting.com states that watercolor is known for "its unique combination of spontaneity, color and the unique blend of painting and drawing skills in one artform." Artists like Winslow Homer, Andrew Wyeth, Paul Cezanne and Paul Klee used watercolor either exclusively or for some of their works. John James Audubon's watercolor illustrations of the animals and birds of America are classic depictions of wildlife in natural settings.

The first watercolors composed of water and natural pigments may well have been used by early mankind to decorate cave walls. Their "brushes" were their own fingers or other items like bones or twigs found in their surroundings. Ancient Egyptian tombs, temples and pyramids have been discovered with pictures on walls done with water-based paints. The ancient Egyptians also decorated papyrus with these paints. In ancient China, Japan, India and Persia, the art of painting in watercolors was developed even further. The Chinese and Japanese watercolor "canvas" was handmade paper or silk upon which they painted landscapes while the Persian and Indian artists painted Muslim religious scenes. In the Middle Ages, monks preserved manuscripts with parchment pages highly decorated with images in watercolor-type paint. During the Renaissance, fresco became a popular form of wall art. In fresco, the artist used moistened pigments and wetted down plaster to create scenes. The moistened pigments were a forerunner of watercolor paints. Once the manufacture of paper became inexpensive, watercolor painting became a popular art form. The well-educated English woman of the eighteenth century learned to paint watercolors. On surveying expeditions throughout the New World, watercolor artists were engaged to record the unusual sights the explorers encountered.

Watercolor paints come in either tubes of pre-moistened pigment or in pans of hardened pigment. Watercolor paint in tubes is easier to use for large areas of a painting. Watercolor paints in a pan are easy to transport when going out of the studio to sketch things in nature. They are useful for small details.

Watercolor paints are composed of microscopic bits of pigment in varying combinations suspended in a medium. The medium usually contains gum arabic as a binder, although synthetically made glycol is also used. The binder ensures the pigment will transfer from the brush to the paper or surface to be painted. A plasticizing agent, usually glycerol or methyl cellulose, keeps the paint from drying out in the tubes by preventing the gum arabic from hardening. A humectant, glucose or honey, is added to keep water from evaporating from the liquid paint and hardening the watercolor paint in the tube. Fillers added to the watercolor paint prevent it from being stringy or shiny when applied to the painting surface. These may be dextrin, gypsum or china clay. About 15 percent of the watercolor paint in a tube is water. Manufacturers may mix in other additives to increase the shelf life of the paints, prevent molds from growing or make the watercolor paint dry more quickly after application.

Watercolor paints in a pan can easily become cross-contaminated with unwanted tints if the brush is not cleaned well enough when going from one color to another. The paint tends to dry out quickly, requiring repeated moistening. The painter may be tempted to grind the bristles of the brush into the watercolor cake, which may wear out the brush quickly. Watercolor paints in a pan tend to cost less than watercolor paints in a tube. Watercolor paints in a tube can be squeezed out with no cross-contamination of colors. Tube paints mix well with water because a little more binder is added to them. A little too much watercolor paint may be squeezed out at one time, leading to waste.