Wool is the dominant material used in Oriental rug pile, and its quality is one of the most important factors determining a rug's beauty, durability, and value. Not all wool is equal — rug-grade wool varies enormously based on multiple factors.
Factors affecting wool quality:
- Breed of sheep — different breeds produce wool with different fiber characteristics. Persian, Turkish, and Tibetan highland sheep produce particularly desirable wool.
- Climate — sheep raised in cold mountainous regions develop longer, more lanolin-rich fleece. The wool from Iranian and Anatolian highland sheep is especially prized.
- Part of the fleece — wool from the shoulder, back, and sides of the sheep is generally finer than wool from the belly or legs. The finest wool of all is called kork (Persian word).
- Age of the sheep — wool from young sheep (especially lambs) is softer; wool from adult sheep is more durable
- Season of shearing — spring-sheared wool, from sheep that have grown a full winter coat, is generally the highest quality
- Spinning method — hand-spun wool (yielding uneven thickness that takes dye more variably) is prized in tribal and village weaving; machine-spun wool (uniform) is standard in workshop production
Notable wool categories in rug weaving:
- Kork wool — the finest wool, taken from the underbelly and neck of the sheep; soft, lustrous, takes dye exceptionally well. Used in fine Persian Kashan, Tabriz, and Nain rugs.
- Manchester wool — a high-grade English worsted wool used in some Persian rugs (especially "Manchester Kashans") in the early-to-mid 20th century; very fine and lustrous
- Merino wool — fine wool from Merino sheep; used in some Australian-import rugs and contemporary production
- Tibetan highland wool — long-staple, lanolin-rich wool from sheep raised at high altitude; the foundation of authentic Tibetan rugs
- Local village wool — varies enormously in quality; in tribal and village rugs, the local wool is part of the rug's regional character
How to evaluate wool quality in a rug:
- Luster — high-quality wool has a natural sheen; very dull wool may be poor grade or chemically washed
- Hand feel — soft and resilient is good; harsh, brittle, or limp is not
- Lanolin content — high-lanolin wool feels slightly oily and develops a beautiful patina with age
- Spring — pressing the pile should leave wool that springs back, not flattens permanently
- Dye absorption — high-quality wool takes natural dyes with rich depth and color variation
Rugs made with high-grade wool age beautifully — developing a softer hand, deeper color, and natural luster over decades. Rugs made with poor-grade wool tend to feel harsh from the beginning and may wear unevenly.