CRAYON

an implement for drawing made from clay, chalk, plumbago, dry colour, and wax. There are two types of crayons, the colouring crayon and the chalk crayon. The colouring crayon, or wax crayon, is the one used by children in making pictures. It consists of waxes such as paraffin, beeswax, and carnauba wax and dry colour. Some synthetic waxlike materials are also used in the modern crayon. The waxes are melted and the dry colour added with continuous mixing until thoroughly dispersed. Normally, the crayon is entirely consumed during the marking process through abrasion. The blackboard crayon, or chalk, that is used in classrooms is commonly composed of calcium carbonate, kaolin clay, oleic acid, and caustic soda. Dry colour may be added to increase the whiteness or to impart specific colours. Modifications of the formulation, such as mixing pigment with a nongreasy binder as with pastels, have provided chalk crayons for more specialized use by artists, tailors, and carpenters. For lithographic prints a plain dark-coloured wax crayon is used to draw an image directly on the stone surface. See also cont crayon; lithography; pastel.