Pigments are a classification of colorants and their fundamental difference from dyes is that they are typically water and oil insoluble. Pigments are used to add colour to various materials ranging from plastics and cosmetic products to industrial equipment and paints. Pigments can be permanent or fugitive (fade over time). Natural pigments can be dated to prehistoric times, while the first use of synthetic pigments can be dated back to the industrial revolution. Organic pigments can be found in food, drugs, cosmetics, paints, coatings, stains etc, while Inorganic pigments can be used in automotive products, cleaning products, paints, cosmetics, cement applications, and various other products.