The primary disadvantage to wool lies in its limited wearability. Wool is a coarse material, which often makes it uncomfortable and itchy to wear. Over time, wool also pills, or forms small balls of fuzz or fabric on the exterior of a garment. In addition, wool is sensitive to the climate it lives in; heat and moisture cause wool to felt, as Love Sewing points out.
Wool also can be difficult to clean. In order to maintain the quality of a sweater made of 100 percent wool, for example, it must be hand-washed and left out to air dry or taken to a dry cleaner for proper care. Although some washable wool blends can be cared for at home, improper care can lead to extreme shrinking of a woolen garment, making it useless.
Wool is made out of sheep's fleece. It can be made in a variety of thicknesses based on the carding process. During this process, the fibers of the fleece are straightened out and then rewoven into a yarn. People are attracted to wool because it is a resilient fabric; a retardant for fire, dirt and static; and a great insulator. For some people however, its disadvantages outweigh its benefits.