Cashmere vs Wool
Cashmere (Capra hircus undercoat, ≤19µm) vs wool (predominantly Merino, 17–24µm): a fine-fiber comparison where cashmere wins on softness and warmth-to-weight, wool wins on durability and value.
Quick Comparison
| Competitor | Winner Axis | Summary |
|---|---|---|
| Cashmere | varies | Compare properties and use cases |
| Wool | varies | Compare properties and use cases |
Decision Summary
Choose cashmere when maximum next-to-skin softness and warmth-to-weight are the primary requirements, you can accept higher cost and delicate care, and the garment will see light duty use. Choose wool (Merino or Superfine) when the garment must resist pilling and abrasion, be worn frequently, or survive more robust washing. At Grade C cashmere (17–19µm), the performance gap versus Superfine Merino is minimal — read the Grade C Trap section before purchasing.
The 22µm Prickle Threshold
Human skin mechanoreceptors register individual fibers protruding from yarn as "prickle" when fiber diameter exceeds approximately 22µm [1]. This is the physical basis for softness as a measurable property, not just a subjective claim. Both Cashmere and Merino wool operate well below this threshold — which is why they are the two fibers that produce genuinely next-to-skin soft knitwear. The key question is where exactly each fiber sits below 22µm, and what that difference means in practice.
Fiber Diameter Comparison
| Grade / Category | Diameter | Classification | Prickle risk |
|---|
|------------------|----------|----------------|-------------|
| Cashmere Grade A | ≤15.5µm | Luxury | None |
|---|---|---|---|
| Cashmere Grade B | 15.5–17µm | Premium | None |
| Cashmere Grade C | 17–19µm | Standard commercial | None (approaching Superfine Merino) |
| Superfine Merino | 17–18.5µm | Premium wool | None |
| Fine Merino | 18.5–19.5µm | Standard Merino | None |
| Medium Merino | 20–22µm | Entry Merino | Near threshold |
| Standard Wool | 24–30µm | Mainstream wool | Above threshold for many wearers |
Head-to-Head Technical Comparison
| Property | Cashmere (Grade A/B) | Fine Merino (18.5–19.5µm) | Advantage |
|---|
|----------|---------------------|--------------------------|----------|
| Fiber diameter | 15–17µm [1] | 18.5–19.5µm | Cashmere |
|---|---|---|---|
| Softness / prickle | Superior | Excellent | Cashmere |
| Warmth-to-weight | Very high (fine + hollow medulla) | High | Cashmere |
| Tensile strength | 9–16 cN/tex [2] | 9–16 cN/tex [2] | Comparable |
| Pilling resistance | Poor (short staple, low crimp) | Moderate | Merino |
| Abrasion resistance | Low | Moderate | Merino |
| Moisture regain | 14–17% | 14–18% [3] | Comparable |
| Odour resistance | Good | Good | Comparable |
| Care requirements | Hand wash / dry clean recommended | Machine washable (Superwash treatment) | Merino |
| Supply per animal | 150–200g/year [4] | Kilograms/year | Merino (abundant) |
| Retail cost multiple | 10–30× Merino | Baseline | Merino |
The Grade C Trap
Mass-market cashmere labeled simply "100% cashmere" often sources Grade C fiber (17–19µm). At this diameter, Grade C cashmere and Superfine Merino overlap entirely on fiber fineness. Grade C cashmere still pills more readily because cashmere staple length is shorter and crimp count is lower — but it commands a price premium purely on the "cashmere" label. A well-made Superfine Merino sweater at Grade C cashmere prices represents better value: comparable softness, higher durability, easier care.
When Cashmere Is Worth the Premium
| Scenario | Why cashmere earns it |
|---|
|----------|-----------------------|
| Grade A/B luxury knitwear (≤17µm) | Measurably finer than any Merino; incomparable drape and handle |
|---|---|
| Light-use dress knitwear | Worn occasionally; longevity concern is lower |
| Extreme warmth-to-weight requirement | Cashmere outperforms Merino at equivalent weight |
| Heritage or gift-register pieces | Cultural and material value; deliberate investment purchase |
Sources and References
[1] Garnsworthy, R.K. et al., Understanding the Basis of Fabric Prickle by Measurement of Mechanical Properties of Single Fibers, Journal of the Textile Institute, 1988. The 22µm prickle threshold study.
[2] Morton, W.E. & Hearle, J.W.S., Physical Properties of Textile Fibres, 4th ed. Woodhead Publishing. Cashmere and Merino tensile and diameter data.
[3] IWTO (International Wool Textile Organisation), Wool Facts. Moisture regain and fiber property reference.
[4] Lupton, D., Cashmere: A Guide to the World's Finest Fiber. Supply per animal and origin data.
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