Watercolor paint is a transparent paint that uses water as a solvent. It was used for wall paintings by Egyptians, Greeks, and Romans. As it came to be used for books and illustrations and became a more popular medium in the 16th through 19th centuries, it was made available in little patties, each in its own metal pan. Today, professional watercolor paints are most often purchased in tubes.

Watercolors are usually applied with a brush, using a variety of techniques, such as wet-on-dry and wet-on-wet, and the so-called dry brush techniques of dry-on-dry and dry-on-wet. Other techniques, such as blotting and combining watercolors with pen and ink, lend variety to the textural appearance.

Watercolor pencils deliver watercolor pigment in a different way. Watercolor pencils can be used dry on dry paper, but when used with water, they work best on watercolor paper, which has the necessary strength. The color intensity will result from how thickly the pencil is applied. One can use watercolor pencils by:

• creating a drawing on dry paper and washing over it
• creating a drawing on dry paper and washing over only particular parts of it
• creating a drawing on wet paper
• dipping the watercolor pencils' tips in water before drawing on dry paper
• drawing on top of work already created and allowed to dry
• combining the use of watercolor pencils and crayons along with brushed on pigment
• wetting the brush and using it to gather pigment from the sharpened end of the pencil

Watercolor pencils are created encased in wood, like regular pencils, and as woodless pencils that are simply pigment wrapped in a thin binding paper. Both kinds of watercolor pencils can be purchased individually or in standard sets. Sets often include sizes 12, 18, 24, 30, and 36, but others increase by increments of ten and include between 10 and 40 pencils.

There are also student sets of watercolor pencils, which often offer fewer colors than professional sets or collections of individual pencils. Classroom packages of 12 watercolor pencils each of 8 basic colors are also available for school use. These are likely to include red, orange, yellow, green, blue, purple, violet, white, brown, and black.