A fixative is an element of a composition that acts as a binding agent for all of the aromatic molecules in a formula that may remain loose and sparsely positioned if left to their own devices. It strengthens a composition, and allows the intricacies of the formula to blend together and mature cooperatively and collectively to produce a superior aroma. It also acts as a preserving agent: imparting qualities of longevity and vitality into a composition, whilst also increasing the lifespan and the overall quality of the fragrance. Fixatives act by reducing evaporation rates through stabilizing and equalizing the vapor pressure, whilst at the same time managing the volatility of the raw materials in the composition. Many types of natural fixatives exist, from resin-based fixatives, to various animal products with fixative tendencies, although the use of the latter has grown largely, if not entirely, out of favor in recent years. The fixatives that have been derived from resins are known as resinoids, and these types of fixatives include the likes of benzoin, myrrh, storax, and labdanum. Synthetic fixatives are also extensively used in perfumery, as they are often inherently low in volatility themselves, like ambroxide. Synthetic products are also often totally lacking in odor, which can be beneficial if the intention is to leave a composition’s aroma unaltered.
One known fixative, coumarin, which also commonly goes by the name tonka bean, is so successful in its fixative tendencies, as well as holding a favourable and memorable aroma, that it’s use in perfumery is seemingly unparalleled. Coumarin is featured in the sizeable majority of all fragrances produced, and the fixative qualities are largely to thank for this reality. Other fixatives are primarily used in the high-end section of the industry, imparting their benefits into compositions with finer and more sought after ingredients. Vetiver is one such example of this phenomenon, who’s properties allow it to have a greater hold on volatile compounds. It is also known for its cooling properties, and also blends well with an assortment of materials, from ionone, to vanilla. Vetiver is often paired with other fixatives like sandalwood for the synergistic benefits.