Lipstick

Lips are one of the most sensitive areas of the human body as they contain numerous nerve endings just beneath the thin membrane surface. These many nerve fibres, running from the brain to the lips, mean the muscles round the lips can be finely controlled to produce different sounds and make speech possible. People also use their lips to express their feelings and communicate a wide variety of emotional states and intentions e.g. smiling and frowning.

The lips also have a rich blood supply consisting of tiny capillaries and larger blood vessels. These are near the surface of the thin skin and provide the soft membrane with its deeper red colour. In an attempt to attract the opposite sex, the blood flow to the lips increases to make them look redder. Some people believe lipstick is used to imitate this state, drawing attention to the lips and making them more obvious so the wearer appears more attractive and fertile.

Most people buy lipstick to make them look and feel good, however, it may be used in different ways. Some people see lipstick as something only to be worn on formal occasions to look smart and other women feel naked without their lipstick. In some sectors of society, lipstick is expected on a woman; and in some cultures it is disapproved of. When people choose to buy a lipstick, they may do so for different reasons e.g. some are influenced by colour, effect (shimmer, glitter, gloss, matt etc.), what it promises to do (moisturise lips, stay on all day, give irresistibly soft, kissable lips etc.), or because of the brand appeal.

Most lipsticks (and certainly lip salves) can also help look after your lips. The ingredients include waxes, which act as a protective barrier – moisturising and protecting the thin skin on the surface of our lips, the epidermis. Today, lipsticks are available in a variety of formats and may act not only to enhance the lips, but also to protect them from sun and wind damage. Many lipsticks now contain sun protection factors to reduce lip damage from UV light.

Lipsticks generally contain waxes, oils, pigments (colours) and emollients (skin softeners). The composition of these ingredients is varied to create different effects:

	Glosses have lots of wax and oil to create a smooth surface on the lips so light is reflected evenly (regular reflection), thus giving shiny lips.
	Matt (not shiny) lipstick contains more pigment, but less oils and emollients for less shine. The surface of the lips is therefore less smooth so light is reflected in different directions (diffuse reflection), giving an even colour.
	Frosted lipsticks contain a compound like crushed synthetic pearl.
	Shimmers contain tiny crystals/particles of mica or silica (like crushed glitter), which catch and reflect the light when it shines from certain angles.

Web links to visit:

	http://www.catie.org.uk/face_value/interactive_home.html
	http://www.schoolscience.co.uk
	http://www.sciencepages.co.uk