There are around 5000 base aromas known to
perfumers, of which around 2000 are used in commercial
perfumery, and less than 500 on a regular basis.
Practically all fine fragrances are constructed in layers.
A top note layer gives the perfume accent.
Top notes are relatively short-lived volatile components
whose main job is provide initial impact and cover the
alcohol evaporation aromas.
Next comes the middle notes, the heart of
the perfume. Middle notes are more enduring and are the most
distinguishable character of the perfume. Middle notes are
often florals or oriental/spicy smells or aromatic herbs.
Finally we have base notes. These are the
longest lasting elements and round the perfume off. Base
notes tie the others together and can add richness, depth
and warmth. Wood, moss, resins extracts are commonly used