Fine Wool - Shearing at Pinewood

The two characterisics valued in wool are the microns and the length of the fleece fibres. When both are apparent the fleece is very valuable, and is sort after by high quality clothing manufactures. A micron (micrometre) is the measurement used to measure the diameter of a wool fibre. The higher the microns the courser the wool fibres the lower the microns the finer the wool fibres. The fibre diameter is important in determining the greasy value of wool. Each fleece comprises a very wide range of fibre diameters depending on the age and health of the sheep. A typical Merino fleece will contain fibres of as low as 10 microns, and fibres up to 25 microns.

Samples can be taken from the side or a fleece and measured using a portable instrument such as an OFDA2000 (Optical Fibre Diameter Analyser); or a mobile instrument system called a Fleecescan. Pre wool classing micron test results are a useful guide for classers in determining lines of wool to be made.

Samples of a fleece can also be sent to a laboratory for measurement. Here the core samples are cleaned, dried and prepared for measurement under strict test methods. Merino wools are normally measured on Laserscan instruments in Australia, New Zealand and South Africa.

Younger sheep's wool is finer and generally more valuable than the wool from older sheep. Most wool between 11.5 and 24 microns in fibre diameter is made into clothing. The remainder is used for other textiles such as blankets, insulation and furnishings.