Merino is a kind of sheep that comes originally from North Africa. In the 18th century they got to Spain, where export to other countries was banned. Nevertheless, they were expanded to France, Austria, Britain and last but not least in the 19th century to Australia, which is now the largest producer of quality merino wool.
There are several types of merino sheep, but all have in common that they have very thin hairs. Per 1 cm square there are up to 4000 hairs.