Decoding Hair

Everything you need to know for a glossy, healthy mane

The only way to truly care for your hair is by knowing exactly what it is, and what damages it most

What do we really know about our hair? Often, it’s surprisingly little. Forget the intricacies of its structure, few can genuinely identify their hair type. Fine strands, even in abundance, may give the appearance of less hair, while fewer but coarser strands could inaccurately suggest greater density. And that’s just one of many uncertainties. Which is why we spoke to Rob Smith, a senior engineer at Dyson’s hair science research programme in England, where they have tested nearly 1,625 kms of hair to study everything from airflow dynamics to its cellular structure. Here, he tells us everything we need to know, from what hair is, exactly, to what damages it most.

GRAND STRANDS

For such a small and thin structure, hair is a complex series of layers. The centre is a bundle of long thin cells called the cortex, comprising keratin fibres less than two billionth of a metre in diameter. Surrounding it is a layer composed of cells, called cuticle, that overlap each other like tiles on a roof and are key to maintaining strength and health. These are actually transparent— it’s the pigment in the cortex that determines hair colour.