Processing a grease fleece for a project – washing, picking, and combing or carding it – is time consuming and nothing is more frustrating than finding that the fleece you plan to process is faulty. A faulty fleece takes longer to process, wastes wool, and may result in poor yarn quality. Knowing the common fleece faults will help you avoid purchasing a bad fleece.

Fleece faults can be divided into three categories:
1. Structural Faults. Problems with the actual structure of the locks of wool.
2. Foreign Matter Contamination. Problems with junk in the fleece.
3. Stains. Problems due to discoloration.

The Structural Faults are:

1. Cotted Fleece. A cotted fleece is matted or partially felted. If the staples are difficult to pull apart and tend to tear or break when pulling them apart, then the fleece is cotted.

2. Pink Rot. The fleece at the point where it appears pinkish is rotted into a felted mass. This usually affects only a small portion of the fleece and it should be removed and left on the skirting room floor.

Next week: Stains and foreign matter contamination.

3. Second Cuts. Second cuts occur when the shearer overlaps blade strokes during shearing. These need to be shaken or picked out of the fleece before washing and processing or they will for neps.

4. Second Cuts. Second cuts occur when the shearer overlaps blade strokes during shearing. These need to be shaken or picked out of the fleece before washing and processing or they will for neps.

5. Tender Fleece. Tender fleece is fleece that breaks at random points in the staple length rather than at a specific point throughout the entire fleece. To check for this, hold a thin lock tightly just as in checking for a break but instead of tugging it, flick it with your ring finger. If it breaks, the fleece is tender.

6. Wool Break. This means that there is a thin, weak spot in the length of the staple. The wool staple will quite literally break apart at the weak spot. To check for this, take a small length of staple, about half the thickness of a pencil and grasp it at both ends. Hold it up to your ear and give it a good, steady tug. If you hear a ripping or tearing sound, that is the staple breaking apart. As fleece breaks occur at the same point in the staple length throughout the fleece, salvaging such a fleece may be possible if the break is near either the tip or butt end. Simply cut the staple at the break.