Merino wool comes from Merino sheep and is composed primarily of keratin protein. Woolmark explains that fibre diameter, measured in microns, and fibre length are important indicators when matching wool to an end use. A micron is one millionth of a metre, allowing very fine differences to be described numerically.

Use Fibre Diameter to Understand a Merino Description

A Merino name is therefore more informative when accompanied by diameter information. Fine fibres are associated with soft apparel, while broader wool fibres can suit bedding or interior textiles. The measurement helps explain a material choice without relying only on how a finished surface looks.