The brilliant pigments of crayons allow children of all ages to color their worlds.
For an artist to apply color to a surface, the two most fundamental requirements are a substance possessing a strong color, which is generally a pigment, and a binder which allows the pigment to adhere to the surface, whether it is a canvas or a piece of paper. Tracing back the history of crayons reveals that they are related to pastels, since they are both sticks of pigment with a binder to hold the pigment to the paper. In the case of crayons, the binder is some sort of wax.
The principle of using wax to hold a pigment onto a surface goes back thousands of years to the Egyptians who mixed pigment and wax, put the combination on a stone surface, and by melting the wax, affixed the color to the surface in a process called encaustic painting. The first examples of sticks of charcoal pigment held together with oil originated in Europe. Rapidly, the idea spread in the United States and Europe that using wax made a more robust drawing tool.
One reason that modern crayons are so popular for use by young children is that considerable effort was put toward making school crayons non-toxic. Many pigments in the late nineteenth and early twentieth centuries were poisonous, so these pigments were avoided or substitutes found. The impact of chemistry on the crayon industry can be seen by comparing pictures of early crayons with today’s products. Modern pigments produce much more brilliant and pure colors compared to the muddier tones of the original crayons. Likewise, the dazzling spectrum of colors now available eclipse the relatively small number of colors sold a century ago. The eight colors available in the original box of Crayola crayons have expanded to 120 different colors as chemists have developed new, brightly colored, non-toxic pigments, allowing budding artists of all ages to express themselves through color.
More background on crayons is available at http://www.crayola.com/about/index.cfm?n_id=6