What is the projection of a perfume?

Sometimes you can smell a perfume only when you approach the person who is using it. And sometimes their scent still lingers for some time in the room they were in. This is the projection of the perfume.

The projection of a perfume is its strength, its intensity, the spatial unfolding of the scent. It can be moderate or strong. 

Perfumes with moderate projection stay close to the skin and are only perceptible when you get close to the person using them. These are subtle, 'unobtrusive' fragrances - usually citrus, aquatic, marine or floral-fruity. They are great for warm days and for work, business meetings or when you know you will be in an enclosed room with others and don't want to overwhelm them with the scent of your perfume. 

Perfumes with strong projection create what is known as a tail or train. They can be smelt from a greater distance and can still be smelt for some time in the room where the person using them has been. These perfumes are usually oriental, oriental-woody, spicy, woody and leathery. They are worth using in cooler weather, for evening outings, parties and special occasions - when you want to draw attention to yourself and shine.