Strearic Acid is a saturated fatty acid found in combined form in natural animal and vegetable fats. It is a colourless, waxy solid that is almost insoluble in water. When it's used in cosmetic products, stearic acid primarily fulfills the role of a thickener or hardener. It is widely used in: Soaps, cosmetics, detergents, lubricants, playing cards, candle making and pharmaceuticals.