Finishing oil seeds of the flax plant, already extensively grown for the production of linen. The raw oil may be used, but it cures poorly and leaves a sticky surface. Normally boiled linseed oil is used. This has been prepared beforehand by boiling with lead, in the form of lead oxide, or with manganese salts. Modern boiled oils use a lead-free metallic drier added cold, such as cobalt resinate. Old linseed oil finishes yellow with age, owing to oxidation with the air. Linseed oil was also widely used for the production of oilcloth, a waterproof covering and rainwear material, formed by coating
Essential oil Essential oil An essential oil is a concentrated hydrophobic liquid containing volatile (defined as "the tendency of a substance to vaporize") aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetherolea, or simply as the oil of the plant from which they were extracted, such as oil of clove. An essential oil is "essential" in the sense that it contains the "essence of" the plant's fragrance—the characteristic fragrance of the plant from which it is derived. The term essential used here does not mean indispensable as with the terms essential amino acid or essential fatty