Perfumes are made up of three notes: The top notes scents that are perceived immediately, usually described as “fresh,” “assertive” or “sharp.” The compounds that contribute to top notes are strong in scent, very volatile, and evaporate quickly. The middle (or heart) notes compounds are usually more mellow and “rounded” emerging as the top notes dissipate. The heart notes form the main body of the perfume. Scents from this note appear anywhere from 2 minutes to 1 hour after the application of a perfume. The base note compounds are often the fixatives used to hold and boost the strength of the lighter top and heart notes. The compounds of this class of scents are typically rich and “deep” and are usually not perceived until 30 minutes after the application of the perfume or during the period of perfume dry-down. A set of city perfumes called “The Scent of Departure” launched in May 2012 designed to remind the wearer of the characteristics of individual cities without ever leaving their home. It is both commercially astute and conceptually clever. Designed by perfumer Gérald Ghislain and designer Magali Sénéquier the fragrances are cleverly packaged as luggage tags incorporating a golden silhouette of a famous landmark or icon from the cities in question. I decided to map them by smell colour. Development work includes calculating colour for each scent used in the perfumes and developing an opacity for each colour based on frequency of occurrence in the range of scents – the more frequently a scent is used the greater it’s opacity.