Crayon is a pen -shaped material that can be used by wax substrates and pigments through uniform mixing and cast molding. At present, crayons in the market are generally paraffin, pigment, calcium carbonate, Vaselin, etc., of which about 70 %, pigments account for 5-10 %, 10 % of calcium carbonate, 10 % of Vaselin. After mixing, heat and stir, and pour into the mold molding. Although this kind of crayon is easy to prepare, 

it is not easy to attach when writing on rubber and tires, and because the tires are mostly dark black, the color rendering effect is not obvious. At the same time The queen is unstable and softened, loosening, and it is more troublesome to clean up. The environment causes pollution and cannot meet the requirements of the use.