Enfleurage is a technique of extracting the aromatic oils from flowers that goes back thousands of years to the days of the pharaohs in Egypt. It works on the simple principle that fats dissolve essential oils and thereby absorb their aromas. Petals and other fragrant plant parts are soaked in fat or non-evaporating oil which absorbs the fragrance. In the 19th century and early parts of the 20th, pork, lard and beef fat were used though now some producers use vegetable fats like palm oil. In the early days, the animal fat was smeared on glass plates in a wooden frame called a chassis and then the flowers were placed on the fat and left to release their oils for several days. The process was repeated several more times with fresh flowers being added to the plates until the fat on the plates was completely saturated with the aromatic oils of the flowers. The oil saturated fat, called a pomade, was then dissolved by alcohol. The aromatic oils migrate to the alcohol which is then separated from the fat and then the alcohol is evaporated to leave the pure aromatic oil of the flower.