Rose in greenhouses, and in warmer countries they may also be grown under cover in order to ensure that the flowers are not damaged by weather and that pest and disease control can be carried out effectively. Significant quantities are grown in some tropical countries, and these are shipped by air to markets across the world. Some kind of roses are artificially coloured using dyed water, like rainbow roses. Rose perfumes are made from rose oil (also called attar of roses), which is a mixture of volatile essential oils obtained by steam distilling the crushed petals of roses. An associated product
Essential oil acid which are so called since they are nutritionally required by a given living organism. In contrast to fatty oils, essential oils typically evaporate completely without leaving a stain or residue. Essential oils are generally extracted by distillation, often by using steam. Other processes include expression, solvent extraction, "sfumatura", absolute oil extraction, resin tapping, wax embedding, and cold pressing. They are used in perfumes, cosmetics, soaps and other products, for flavoring food and drink, and for adding scents to incense and household cleaning products. Essential oils are often used for aromatherapy, a form of alternative medicine in which healing effects