Ivory Black is named so because the pigment used in its creation was derived from the charred bones of dead animals, a practice accredited to the ancient Romans. The pigment from the bones was further refined and added to oil where it was used as a primitive form of oil paint. There were originally two forms of black paint, one a more basic type that was made from the bones of ordinary animals, and another higher grade that was made from ivory, resulting in a purer denser colour. Naturally, ivory is no longer used in the creation of pigment of this paint, but the name and the reference remain. Although the practice of using charred animal bones to create pigment may seem archaic, this same method is still used to create Ivory Black today, except the bones of endangered animals are no longer used. The skull and spine are also not used since the advert of Mad Cow Disease. The bones are heated to extreme temperatures in an oxygen-depleted atmosphere to control the quality of what is known as the black bone. The grade of this product is indicated by the colour and absence of impurities. The darker the colour, the higher the quality.