What’s their secret, you can’t help but wonder? How are their smiles so achingly bright, their hair so impossibly full and bouncy?
It’s hardly a new idea — the business of adding hair to your head, whether fake or human, has been booming since Ancient Egyptian times.
Yet, keeping them subtle is quite a challenge. Here, we investigate the pitfalls of the secret world of hair extensions.
A common form of extension is the weave, a long strip of hair tied at the top with very fine, strong thread.
This can simply be clipped into the hair with grips, for a temporary fix — although this type often slips out and is easier to spot than permanent ones.
Alternatively, a weave can be sewn directly to a layer of your hair.
In a third method, the LA weave, tiny metal loops known as “micro-rings” are sewn along the top of a strip of hair strands.
Each micro-ring is slipped around a few strands of your natural hair. Finally, the metal rings are crushed with a device like pliers, flattening them and clamping them onto your hair.
There are also the more traditional single-strand extensions.
Each strand consists of a bunch of about 100 individual hairs which is fastened on to your own locks beneath the top layer of your hair, using a glue containing keratin, a natural component of hair.
Karl explains that a full head of hair will require 150 to 200 strand extensions between 16in and 24in long.
The glue is melted with a special heat gun, then hardens as it dries, sticking your hair and the extension together.
Other methods include attaching extensions with special tape.
No clip-on hair, however well applied, will last more than a couple of days.
A synthetic weave will last about four weeks, while a high-end set of real human hair extensions might look sleek for three months.
After that your own hair will have grown, so the extensions will be much lower down on the hair shaft and start to look messy.