English version.
STRUCTURE OF THE PERFUME
We can continue , altought I am feeling the " great loneliness " of the perfumer.
I talked about the solvent , now I am going to consider the solute , ie the mixture of perfume.
This concoction is composed of both natural and synthetic materials , which , according to their physical and chemical characteristics, play a specific role in the structure of the scent.
On the basis of their volatility, which indicates the tendency to evaporate , for example , in the classic olfactory pyramid of the perfume, these will constitute the notes of :
Top or head : these are the first notes we perceive sniffing the perfume , formed by molecules with high evaporation, so they do not last long, but they are important to lend impact to the perfume.
Typical odorants of head are Hesperides materials, ie citric ,like bergamot , lemon , petitgrain , mandarine , orange...
or of :
Heart : these notes appear after the top notes and they are the core of the perfume , having a volatily intermediate between the head and the base.
Typically belong to this class the floral and spicy notes.
or of:
Basis : these are the notes of bottom or drydown , the last to appear, but the most persistent and tenacious , fixing the scent.
To this class belong the woody materials like sandalwood , cedar , patchouli; musks and balms .
But the olfactory pyramid should not be seen as a tightly partitioned structure , because the three levels - top , heart and basis - are not separate , but interrelated by materials that act like a bridge , so that the perfume has a continuity , has its characteristic features , which are modulated , but not overturned along the olfactory journey .
The perfume must be well balanced and should last , hence the three notes have to be prorated according to optimal proportions.
For good fixation and persistance , the basis must be substantial.
Its percentage goes from 40 to 50% and more.
Top and heart notes can occupy each from 20 to 30% of the formula.
Of course , this is not a dogma , and the formulation of the perfume can undergo more or less wide variations depending on the needs of the perfumer , on his creative inspiration and on available materials.