They call them flat or ‘cashmere’ lashes

Traditional eyelash extensions are like tapering cylinders – seen from either end, they are round. If you want a thicker lash, you get a wider cylinder. If you want a longer lash, you get a longer cylinder. Each choice means a corresponding increase in the weight of the cylinder. Since you can only put on a natural lash as much weight as it can reasonably carry, the thickness and strength of your natural eyelashes limits the thickness and length of lash extensions you can have. If your natural hair is fine or not particularly strong, then you can only have very fine and quite short extensions. It’s only those with thick natural hair who can carry off the thickest and longest glamorous silk extensions.

Help is at hand in the form of a new type of lash, called flat lashes. With these, the normal lash extension is squashed, so that the cylinder is no longer round but an ellipse – i.e. more like a rugger ball, seen from the side, than a football – and then you can have thicker, but not heavier, eyelash extensions.

If your eyelashes can only carry normal extension lashes which are 0.10 mm thick, using flat lashes you may be able to wear 0.12 mm or 0.15 mm, without any additional weight. These new types of extension are not widely used, but they may be the way to go for those with fine or weak lashes. In fact, a flat eyelash 0.15 mm thick is actually about as heavy as a traditional lash 0.07 mm thick.

These lashes will give your eyes a much fuller look, but they won’t put any additional strain on your natural lashes.

Another benefit of these new squashed type of lashes is that they’re not just squashed into an oval shape, but can be made concave on two sides, so that the side being glued onto the natural lash will actually grip the circular natural lash much more closely, which means a much better hold for the glue. This may reduce the number of extensions which fall off the natural lashes over the weeks following the treatment, and that may mean fewer infills.

These flat lashes are marketed as ‘cashmere’. Cashmere lashes are not really made of cashmere, any more than silk or (usually) mink lashes advertised as such are actually made of those natural products. They are  made of polymer. So are ‘cashmere’ lashes. ‘Cashmere lashes’ is only a trade name. Wherever you see the name you’ll see the little ® sign for registered design (like copyright or patent protection), but I suspect this is wishful thinking, because I can’t see how you can protect the name of an animal’s hair. So, you may well see other cashmere-named products appearing.