Sillage in perfume refers to the trail created by a perfume when it is worn on the skin). It comes from the French word for "wake" and can best be described as how a fragrance diffuses behind the wearer as they move). Sillage is not to be confused with a perfumes projection, which refers to how far away people can smell it. A fragrance does not need to be a heavy one to have a large sillage). Sillage can be affected by many factors, including the type of perfume, the weather, and even the wearers mood. Heavier scents will have more noticeable sillage, while lighter scents will have less. The inherent scent of the individual skin, moisturization of the skin, the behavior of the microbiome of the skin, and the temperature of the surface of the skin that the fragrance is applied to will affect the sillage or diffusion of a perfume applied to it). Compounds such as Hedione, damascones, Iso-E super, linalool, and some of the synthetic musks such as cashmeran may also be added to fragrances to enhance their diffusion and sillage). A perfumes sillage is considered one of the most powerful characteristics of a fragrance. It can correlate with memory, and the smell of a particular fragrance may bring back memories of a specific person, even if that person is not actually there at that exact moment or is no longer present in the physical world.