Video provided courtesy of The Woolmark Company

Composition of the Fibre

Wool is composed of a natural protein called keratin, the same protein found in human hair. It also contains a small amount of calcium, sodium and fat.

Merino wool can be softer than cashmere and smoother than silk.

Image provided courtesy of The Woolmark Company

Wool has a unique scale structure, with differing patterns depending on the animal which they come from. Cellulosic fibres – cotton, silk and linen – and synthetic fibres such as polyester do not have these unique scales. These scales are important for protection, felting behaviour and the handle of finished products. They also provide a natural water-resistant surface.

Wool can be divided into three main categories, based on the micron (diameter) of each fibre. One micron is equal to one millionth of a metre and fibre length is recorded in millimetres – these are the main measurements which determine the quality and use of the wool.


Wool with the finest micron comes from Merino sheep and is used for high-quality, soft-handling fabrics and knitting yarns. Vanessa Bell producers her own fine Merino wool from her Goulburn property in the Southern Tablelands of New South Wales, Australia.


Medium micron wool can be produced from a type of Merino or produced by crossing one breed with another (crossbreeding). Medium wools are used in a variety of woven apparel cloths, knitting yarns and furnishings.


Many different sheep breeds produce broader wools. Often these breeds are known as dual-purpose breeds because they are farmed with equal emphasis on meat and wool. Broad wool is useful for products such as carpets because of its strength and durability.

The average micron of human hair is between 50 to 100 micron. Merino wool is generally less than 22 micron, demonstrating the softness of this premium fibre.