Watercolors have been a choice of medium for many artists and illustrators over the years. They are relatively inexpensive and easy to use "on site".
Watercolors are noted by their translucency. Although white is sometimes available as a color, most watercolor purists accept that the "whites" should be produced by the whiteness of the surface. By varying the amount of water used to thin the paints, a range of value can be produced.
Watercolors are mostly used on papers. Watercolor papers are available in a variety of thicknesses and "tooth". Thicker papers are able to accept more water without wrinkling and are generally more expensive.
Watercolor paints are produced as dry cakes that activate when water is added to them. They also come in tubes like traditional paints.