Perfume on paper
Perfume manufacturers can advertise their products by actually enclosing the fragrance in a leaflet or a magazine page. Because the smell of the perfume is released by rubbing or scratching the paper surface, the method is known as microfragrance or `scratch ‘n’ sniff.
The scent is in minute capsules too small to see, laid on the paper in a resinous coating. The capsule shell is a plastic that breaks to release the essential oils of the perfume inside when it is scratched or rubbed. The technique, known as microencapsulisation, was pioneered by an American company, 3M, in the 1960s.
To fill the capsules, the oil is shaken up with water to break it up into tiny droplets – rather like shaking a salad dressing of oil and vinegar. Then the droplets are scattered on a surface and covered with a layer of plastic resin.
They are left to set – or sometimes they are heated – before being coated to the paper with another resin. They are sometimes in an adhesive coating in the fold of a leaflet, and the fragrance is released as the coating breaks when the paper is unfolded.
Some cosmetics now contain micro-capsules of skin-nourishing oils. They are not released until the preparation is applied to the skin, which ensures that they stay fresh in the container.