Crayon Rocks are all natural soy wax crayons made from USA grown soybeans and colored with mineral pigments. The colors are vibrant and can be layered to make beautifully textured art work. They were designed to strengthen the tripod grip muscles, preparing fingers and hands for handwriting. The shape allows small fingers to color in large, wide strokes creating pictures rich in color. Used by occupational therapists to develop fine motor skills.