What is the difference between an Eau de Parfum and an Eau de Toilette?

An eau de parfum is not simply a more concentrated version of an eau de toilette. 

It is a more intense but also different take on the olfactory story. The perfumer (‘the nose’) highlights one of its character traits using new ingredients or a new accord while remaining faithful to the original story.

The Do Son eau de toilette, for example, evokes the fresh, intoxicating fragrance of tuberose carried on the sea breeze of Along Bay. The eau de parfum, meanwhile, is an interpretation of the flower at dusk in a wooden pagoda, the tuberose more persistent here, with a more woody note.