Wool Quality

Sheep grow an average of 8 pounds (3.6kg) of wool each year.

It takes a year for the sheep to grow a complete fleece of wool. sheep

Wool is the fibre derived from the fur of animals of the caprinae family, principally sheep, but the hair of certain species of other mammals such as goats, llamas and rabbits may also be called wool. This article deals explicitly with the wool produced from domestic sheep.

Wool has two qualities that distinguish it from hair or fur: it has scales which overlap like shingles on a roof and it is crimped; in some fleeces the wool fibres have more than 20 bends per inch. Wool straight off a sheep contains a high level of grease which contains valuable lanolin as well as dirt, dead skin, sweat residue, and vegetable matter. This state is known as "grease wool" or "wool in the grease".

Before the wool can be used for commercial purposes it must be scoured, or cleaned. Scouring may be as simple as a bath in warm water, or a complicated industrial process using detergent and alkali. In commercial wool, vegetable matter is often removed by the chemical process of chemical carbanization. In less processed wools, vegetable matter may be removed by hand, and some of the lanolin left intact through use of gentler detergents. This semi-grease wool can be worked into yarn and knitted into particularly water-resistant mittens or sweaters, such as those of the Aran Island fishermen. Lanolin removed from wool is widely used in the cosmetics industry, such as hand creams. After shearing, the wool is separated into five main categories: fleece (which makes up the vast bulk), broken, pieces, bellies and locks. The latter four are pressed into wool packs and sold separately. The quality of fleece is determined by a technique known as wool classing, whereby a qualified wool classer groups wools of similar grading’s together to maximise the return for the farmer or sheep owner. Prior to Australian auctions all Merino fleece wool is objectively measured for micron, yield (including the amount of vegetable matter), staple length, staple strength and sometimes colour and comfort factor.


Virgin wool is wool spun for the first time, as contrasted with shoddy.

Shoddy or recycled wool is made by cutting or tearing apart existing wool fabric and re-spinning the resulting fibres. As this process makes the wool fibres shorter, the remanufactured fabric is inferior to the original. The recycled wool may be mixed with raw wool, wool noil, or another fibre such as cotton to increase the average fibre length. Such yarns are typically used as weft yarns with a cotton wrap. This process was invented in the Heavy Woollen District of West Yorkshire and created a micro-economy in this area for many years.

Ragg is a sturdy wool fibre made into yarn and used in many rugged applications like gloves.

Worsted is a strong, long-staple, combed wool yarn with a hard surface.

Woollen is a soft, short-staple, carded wool yarn typically used for knitting. In traditional weaving, woollen weft yarn (for softness and warmth) is frequently combined with a worsted warp yarn for strength on the loom.

Quality of Wool

The quality of wool is determined by the following factors, fibre diameter, yield, staple length, colour and staple strength. Fibre diameter is the single most important wool characteristic determining quality and price. Merino wool is typically 3-5 inches in length and is very fine (between 12-24 microns. The finest and most valuable wool comes from Merino hogget’s. Wool taken from sheep produced for meat is typically more coarse, and has fibres are 1.5 to 6 inches in length. Damage or "breaks in the wool" can occur if the sheep is stressed while it is growing its fleece, resulting in a thin spot where the fleece is likely to break. Wool is also separated into grades based on the measurement of the wool's diameter in microns. These grades may vary depending on the breed or purpose of the wool.

For example.

17.5 - Ultrafine merino

17.6 -18.5 - Superfine merino

19.5 - Fine merino

19.6 - 20.5 - Fine medium merino

20.6 - 22.5 - Medium merino

22.6  - Strong merino


 24.5 - Fine

 24.5 - 31.4 - Medium

 31.5 - 35.4 - Fine crossbred

35.5  - Coarse crossbred

In general,, anything smaller than 25 microns can be used for garments, while coarser grades are used for outerwear or rugs. The finer the wool, the softer it will be, while coarser grades are more durable and less prone to pilling.

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