In order to understand why there are so many different types of human hair extensions available, it helps to start with an understanding of the structure of natural human hair.The structure of human hair is made up of a number of layers. The outer layer, called the ‘cuticle’ is a formation of overlapping scales, with their free edges pointing downwards towards the tip of the hair strand. When viewed under a microscope the cuticle scales have an appearance similar to the tiles on a roof with each one lying on top of the other.
The purpose of the cuticle is to lock in essential moisture and to protect the hair against outside elements. It also gives hair its characteristic appearance. Hair without a cuticle would appear dull and lifeless, and would dry out and become brittle.
A healthy cuticle has smooth, flat scales, which reflect the light, making the hair look shiny and feel silky. Damaged hair has raised cuticle scales, making the hair’s surface feel rough and the hair will look dull and lack sheen.
When applying real human hair extensions it is essential that the hair is applied in the direction that it was naturally grown, from root to tip. If the hair’s alignment is mixed up or attached upside-down, the cuticle scales will catch on each other and interlock like Velcro causing the hair to mat constantly. Brushing the hair will not relieve the condition and in any case, it will just continue to tangle up again. Therefore, correct alignment is crucial when applying hair extensions. Hair aligned correctly from root to tip is known as ‘cuticle correct hair’.