Khullu (Yak Wool)

Yaks have a coarse outer coat to shed wind and weather, and beneath it a remarkably fine layer of insulating down called khullu. This soft undercoat, typically about 16–20 microns in diameter, keeps yaks warm through the bitter winters of the Tibetan Plateau. Khullu makes an exceptional sweater fiber: soft enough to wear next to the skin, warm without being heavy, breathable, and naturally resistant to odors. It also stands up well to regular wear.

Khullu is a renewable natural fiber, gently combed from yaks as they shed their winter coats each spring. Yaks are well suited to the fragile high-altitude grasslands where they graze, and, unlike cashmere goats, graze without pulling plants out by the roots. Oliver Charles sources its khullu through a traceable Tibetan cooperative that supports local communities and grassland conservation. Durable, biodegradable and requiring relatively little washing, khullu fits well with the simple idea of buying good clothing and wearing it for a long time. Like many of the best natural materials, khullu is quite simply well suited to the job.