information:filtering
Imprecise terminology

The wide range in the percentages of aromatic compounds that may be present in each concentration means that the terminology of extrait, EdP, EdT, and EdC is quite imprecise with regard to oil concentration. Although an EdP will often be more concentrated than an EdT and in turn an EdC, this is not always the case. Different perfumeries or perfume houses assign different amounts of oils to each of their perfumes. Therefore, although the oil concentration of a perfume in EdP dilution will necessarily be higher than the same perfume in EdT from within a company's same range, the actual amount will vary among companies. An EdT from one house may have a higher concentration of aromatic compounds than an EdP from another.

Furthermore, some fragrances with the same product name but having a different concentration may not only differ in their dilutions, but actually use different perfume oil mixtures altogether. For instance, in order to make the EdT version of a fragrance brighter and fresher than its EdP, the EdT oil may be "tweaked" to contain slightly more top notes or fewer base notes. Chanel No. 5 is a good example: its parfum, EdP, EdT, and now-discontinued EdC concentrations are in fact different compositions (the parfum dates to 1921, the EdT from the 1950s, and the EdP was not developed until the 1980s). In some cases, words such as extrême, intense, or concentrée that might indicate a higher aromatic concentration are actually completely different fragrances, related only because of a similar perfume accord. An example of this is Chanel's Pour Monsieur and Pour Monsieur concentrée. This complexity adds a layer of nuance to the understanding and appreciation of perfumery, where variations in concentration and formulation can significantly alter the olfactory ("the sense of smell") experience.