Sillage is the scent trail left behind as you move through a space, while projection is how far the fragrance radiates outward from your skin at any given moment — related, but genuinely not the same thing.

Why the distinction matters in practice

A fragrance can have strong projection but weak sillage if it creates a noticeable bubble around you while you’re standing still but doesn’t leave much of a trace once you walk away. Equally, a scent can have a lingering trail (good sillage) without ever feeling especially strong close to your skin. Understanding both helps explain why two ‘strong’ fragrances can behave quite differently in the same room — one might announce itself immediately and fade from the space quickly, while another builds more gradually but lingers longer after you’ve gone.

  • Projection: how far scent radiates from your skin right now
  • Sillage: the trail it leaves as you move
  • Both are separate from longevity, which is simply how long it lasts overall

Understanding this difference is genuinely useful when reading reviews, since someone describing ‘huge sillage’ but ‘weak projection’ is telling you something quite specific about how a fragrance behaves, not offering a contradiction.

Our guide to how perfume is made breaks all three down properly, and our complete guide to perfume is a useful primer if these terms are new to you.