In perfumery, a fixative is a natural or synthetic substance used to reduce the evaporation rate and improve stability when added to more volatile components. This allows the final product to last longer while keeping its original fragrance. Fixatives are indispensable commodities to the perfume industry. Some examples of fixatives are ambergris

Ambergris

Ambergris is a solid, waxy, flammable substance of a dull gray or blackish color produced in the digestive system of and regurgitated or secreted by sperm whales....

, sandalwood

Sandalwood

Sandalwood is the name of a class of fragrant woods from trees in the genus Santalum. The woods are heavy, yellow, and fine-grained, and unlike many other aromatic woods they retain their fragrance for decades. As well as using the harvested and cut wood in-situ, essential oils are also extracted...

, musk

Musk

Musk is a class of aromatic substances commonly used as base notes in perfumery. They include glandular secretions from animals such as the musk deer, numerous plants emitting similar fragrances, and artificial substances with similar odors. Musk was a name originally given to a substance with a...

, vetiver

Vetiver

Chrysopogon zizanioides, commonly known as vetiver , is a perennial grass of the Poaceae family, native to India. In western and northern India, it is popularly known as khus. Vetiver can grow up to 1.5 metres high and form clumps as wide. The stems are tall and the leaves are long, thin, and...

, orris root

Orris root

Orris root is a term used for the roots Iris germanica, Iris florentina, and Iris pallida. Once important in western herbal medicine, it is now used mainly as a fixative and base note in perfumery, as well as an ingredient in many brands of gin....

, and bergamot orange

Bergamot orange

Citrus bergamia, the Bergamot orange, is a fragrant fruit the size of an orange, with a yellow colour similar to a lemon. Genetic research into the ancestral origins of extant citrus cultivars recently matched the bergamot as a likely hybrid of Citrus limetta and Citrus aurantium...

. In some instances, such as soapmaking, castor oil

Castor oil

Castor oil is a vegetable oil obtained from the castor bean . Castor oil is a colorless to very pale yellow liquid with mild or no odor or taste. Its boiling point is and its density is 961 kg/m3...

, may be used. Natural fixatives usually have a fragrance considered a base note in perfumery terms, reflecting their low volatility.