The morning routine is something we do without a second thought. Get up, brush teeth, get dressed, go to school or work. But our toothpaste, our contact lenses and even the humble zip are far from simple products.

Toothpaste
Most of us wouldn’t set foot out of the door in the morning without first brushing our teeth. But what exactly are we putting into our mouths?

Toothpaste consists of active and inactive ingredients. The active ones contribute directly to oral hygiene; the inactive ones give the paste its colour and texture. Active ingredients include fluoride, antibacterial agents, desensitizing agents to make our teeth less sensitive, anti-tartar agents and enzymes, which enhance the anti-bacterial properties of our saliva. Inactive ingredients can include water, humectants, which give the paste its texture, detergents to make the toothpaste foam, and flavourings.

Striped toothpaste is made by having pastes of two colours contained within separate chambers in the packaging. Squeezing the tube pushes the paste through separate parts of the nozzle, creating the striped effect.

Contact lenses
For millions of people with imperfect vision, contact lenses are a godsend. And over the past few years soft, daily-disposable lenses have revolutionized wearers’ lives.

Contact lenses work by sitting on the surface of the eye and correcting vision by bending light so that it focuses on the retina. Both soft and hard lenses are made from special polymers. In 1962 Czech scientists invented a transparent ‘hydrogel’ plastic called hydroxymethylmethacrylate, which consists largely of water. They showed that the substance could be formed into lenses that would fit exactly over the eye’s surface.

Nowadays most lenses are made by a process called lathe cutting. When the lens material is dry it is rigid. In this form it is cut on a lathe and polished before being exposed to water where it hydrates and becomes soft.

Zips
Zips are integral to our clothing. The zip is a remarkable piece of precision engineering. It consists of two rows of teeth. Each tooth possesses a dome – or hook – and a hollow.

When the rows of teeth are brought together, the dome of one tooth fits into the hollow of its opposite number on the other row. The rows are pushed together and pulled apart by the slider, a Y-shaped wedge. As the slider is pulled upwards, the wedge forces the two rows together, making the teeth slot into one another. When the slider is pulled down, the two rows of teeth are forced apart.

Zips depend absolutely on all the teeth being the same size and shape, and being in the perfect position on the track.