Fragrance, also known as perfume or cologne, is a combination of aromatic compounds that is applied to the skin to produce a pleasant smell. Perfume may be derived from natural essential oils, or from synthetic aroma chemicals such as vanillin or coumarin. Ancient texts and archaeological excavations suggest that perfumery was practiced by some of the world’s earliest civilizations. The International Fragrance Association lists over 3,500 different fragrance chemicals used in perfumes and colognes.
Manufacturers of perfume and cologne mix fragrant raw materials together to create custom fragrance compositions. Companies that sell scented products, such as perfumes and colognes, purchase these mixtures from fragrance houses (companies that specialize in the development of fragrance chemicals).
Perfume ingredients are classified into five groups loosely based on their concentration of aroma chemicals. The highest concentration of perfume chemicals is found in parfum, or extrait, which has about 20-30% perfume concentrate. The lowest concentration is in toilet water or cologne, which usually contains about 2-6% perfume concentrate. Perfume and colognes are mainly alcoholic solutions of perfume compounds, but can also contain other substances such as fixatives to prevent the more volatile components of the fragrance from evaporating too quickly.
The top notes are the first scents to assert themselves when a perfume is sprayed or dabbed on. The most common top notes include citrus, clementine and grapefruit, along with florals such as rose and jasmine.
Middle notes are the next scents to appear in a perfume, after the initial dissipation of the top notes. Florals, spices and botanicals are the most common middle notes.
Base notes are the heaviest and longest-lasting notes in a perfume, providing depth and stability to the other scents. Base notes are often reminiscent of woods, mosses and amber, but they can also be quite complex and exotic.
A flanker is a new release of an existing perfume with one or two key alterations to the formula. Fragrance flankers are more common in mainstream perfumery than with niche brands, but they are becoming increasingly popular in many countries. Examples of flankers include the Chanel Coco Mademoiselle and Thierry Mugler A*Men Pure Malt fragrances.
Certain animal secretions contain odoriferous compounds that act as fixatives, increasing the longevity of a perfume’s scent. These are generally employed in alcoholic solutions, and include ambergris from sperm whales, castoreum from beavers and civet from the musk deer.
The trail of a perfume on the wearer’s skin is called its sillage. This trail is determined by the concentration and blend of the fragrance’s middle and base notes. A higher percentage of middle and base notes results in more sillage, while a lower percentage produces less. Fragrance sillage can also be impacted by the wearer’s mood, which is why some perfumes change over time as the wearer becomes more or less accustomed to a particular fragrance. The sillage created by a perfume is also dependent on the humidity of the environment in which it is worn.