Top Notes provide the first scent impression of a fragrance once applied to the skin. They are lighter, more volatile aromas that evaporate readily. Their scent lingers for between 5 to 30 minutes. Middle Notes sometimes referred to as 'heart notes', make up the body of the blend. They may be evident from the start, but will usually take 10-30 minutes to develop on the skin thoroughly. Base Notes are those with the highest molecular weight. They last the longest and are also important as fixatives, that is, they help slow down the evaporation rates of the lighter notes, giving the fragrance holding power. Typical base notes include oakmoss, patchouli, woods, musk and vanilla.