The softness of Merino wool
Do you have a bad memory of an "itchy wool" sweater? Try again with Merino wool!
First and foremost, you must understand why standard wool itches: it's a question of the thinness of the strand and hairiness of the wool.
Remember that wool has an uneven surface that traps insulating warm air. The scales can then grip the skin and create an uncomfortable tingling feeling.
Moreover, if the wool strand is thick, it loses flexibility and it touches the skin more during our different movements, increasing the gripping points and itchy feeling.
Now for a little bit of history: the Merino sheep is a breed of Spanish sheep, whose ancestors have been selected from generation to generation, for the thinnest wool possible.
The thinness of the wool from Merino sheep gives it great flexibility, which means less skin contact and a soft, comfortable feeling.
As a comparison, the thinness of Merino wool varies between 16 and 19 microns, whereas that of standard wool is between 20 and 25 microns and a hair is between 70 and 120 microns.
On the photo opposite, you can see the thinness of a fibre of Merino wool on the left, compared to a human hair on the right (Photo credit: ©CSIRO).
However, it should be noted that for extreme softness, it's better to go for a fabric made from very smooth fibres that don't grip to the skin.