Top note

Notes in perfumery are descriptors of scents that can be sensed upon the application of a perfume. Notes are separated into three classes; top/head notes, middle/heart notes, and base notes; which denote groups of scents which can be sensed with respect to the time after the application of a perfume. These notes are created carefully with knowledge of the evaporation process and intended use of the perfume. The presence of one note may alter the perception of another - for instance, the presence of certain base or heart notes will alter the scent perceived when the top notes are strongest, and likewise the scent of base notes in the dry-down will often be altered depending on the smells of the heart notes.

The idea of notes is used primarily for the marketing of fine fragrances. The term is sometimes used by perfumers to describe approximately scents or the perfumery process to laypeople.

Fragrant materials are listed by Poucher in order of volatility and are grouped under respective evaporation coefficients (perfume notes) that range from 1 to 100.

Top notes are otherwise called the head notes.

Perceived immediately upon application of a perfume, top notes consist of small, light molecules that evaporate quickly. They form a person's initial impression of a perfume and thus are very important in the selling of the product. The scents of this note class are usually described as "fresh," "assertive" or "sharp." The compounds that contribute to top notes are strong in scent, very volatile, and evaporate quickly.

Although not as saliently perceived, the heart and base-notes contribute much to the scent in the top notes.

Citrus and ginger scents are common top notes.

They are also called the "heart notes".

The scent of a perfume that emerges just prior to when the top notes dissipate. The middle note compounds form the "heart" or main body of a perfume and emerge in the middle of the perfume's dispersion process. They serve to mask the often unpleasant initial impression of base notes, which become more pleasant with time. Not surprisingly, the scent of middle note compounds is usually more mellow and "rounded." Scents from this note class appear anywhere from two minutes to one hour after the application of a perfume.

Lavender and rose scents are typical middle notes.

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