Another key component of the Mondeluz Cololored Aquarelle pencil is the use of the highest quality bleached kaolin white clay. This clay gives these colored pencils an unsurpassable ability to make dense strokes that lay down beautifully on many surfaces. The finest binders and additives are also combined into this unique formula to ensure excellent solubility of all components. The 3.8mm diameter lead is encased in California Cedar for easy sharpening. The final product is non-toxic and suitable for all ages.