The addition of magnesium oxide in crayons serves several purposes

Firstly, it enhances the smoothness of the crayon. Magnesium oxide, an inorganic compound with a powdery appearance, when mixed with wax, makes the crayon glide more smoothly and easily on paper, providing children with a more fluid drawing experience.

Secondly, the addition of magnesium oxide improves the wear resistance and fracture resistance of the crayon. By increasing the hardness of the crayon, magnesium oxide makes it more durable and less prone to breakage. This means that the crayon can withstand more usage and pressure, resulting in a longer lifespan.

Furthermore, magnesium oxide helps adjust the hardness of the crayon. Manufacturers can modify the amount of magnesium oxide according to the desired hardness of the crayon. By adding different proportions of magnesium oxide, crayons with varying degrees of hardness can be produced, catering to different drawing techniques and requirements. Artists who want to create finer lines may prefer harder crayons, while those who enjoy softer colors and blending effects may find softer crayons more suitable.

Additionally, magnesium oxide can also contribute to adjusting the color saturation of the crayon. It affects the scattering and reflection of pigments, thereby altering the brightness of crayon colors. Manufacturers can obtain colors of different levels of brightness by adjusting the proportion of magnesium oxide. As a result, children using crayons have a wider range of color choices, adding more vibrancy and richness to their artwork.

However, it is important to note that safety precautions should be observed when using crayons. Although magnesium oxide is non-toxic, prolonged inhalation of dust may cause irritation to the respiratory system. Therefore, when using crayons, especially by children, it is advisable to ensure a well-ventilated environment and avoid inhaling crayon dust.

In conclusion, the addition of magnesium oxide in crayons serves the purpose of enhancing smoothness, improving wear resistance and fracture resistance, and adjusting hardness and color saturation. This seemingly inconspicuous ingredient brings better performance and user experience to crayons.