When the mercury drops and winter’s freeze sets in, millions around the world search for the warmest, coziest garments money can buy. Two of the most coveted fibers – cashmere and alpaca – have woven their way into the fabric of high-end fashion. But which yarn wins out in terns of value and for insulation?

Cashmere: A Classic

A historical favorite for shawls and sweaters, strong-but-soft-and-light-beyond-dreams cashmere became popular in the 1980s, taken up by designers for everything from jackets to sweatpants.

For many years, it was deemed the most luxurious wool of them all. Why? For its über-strict and painstaking manufacturing process. In order to be labeled "cashmere," the fabric must contain fibers from the downy undercoat of the fleece of a particular breed of goat (traditionally from India's Kashmir region) and pass specific measurement requirements. The finest cashmere consists of only the whitest, longest, thinnest hair from the goat’s underfleece. The hairs must be more than 36mm long to qualify as premium.

Cashmere's status began to change in the 1990s when China began to produce it in mass volumes, essentially ‘devaluing’ the fiber from luxury to mainstream. Cashmere, very swiftly, went from wool royalty (with a hefty price tag to match) to being available pretty much everywhere, at a moderate price. Although the premium variety from India still comes at a high cost, these days you can pick up a “cashmere" sweater for as little as $80.

Generally speaking, the lesser price reflects a lower-quality fiber – typically shorter, coarser hair from a goat's undercoat (only 28-30mm long), or fabric blended with yak or rabbit hair. To make things worse, these garments are knitted loosely, so the customer not only gets substandard material, there’s less of it.

In That Corner: Alpaca

Cashmere became so mass-produced that couturiers began searching for a rarer, more exclusive alternative. This opened the gates to a new hoofed critter, the alpaca, a camelid cousin of the camel and the llama. Actually, Peruvians had been wearing knits made of alpaca fiber for centuries, but now, the silky-soft secret spread to the fashion world, and high-end designers began flocking to use the fleece of the shaggy South American native.

Once called the poor man’s cashmere, alpaca has made it to the head of the pack in the designer-garment universe; many now believe its yarn is more luxurious, slightly softer, lighter and warmer thanks to its longer fibers. It also pills less than cashmere and is hypoallergenic, not to mention rarer: There are an estimated 4 million alpacas – and by contrast, around 450 million cashmere goats – worldwide.

Alpaca weaving is a traditional craft, done using sustainable methods, which puts it under the desirable “Fair Trade” banner. This, combined with the ability to create high-end designs using a lesser-known fiber, are among the reasons alpaca wool has gained such a prominent luxury fashion following. Design houses that have warmed to alpaca include Giorgio Armani, Max Mara and Nanette Lepore. Even Loro Piana, famed purveyor of fine cashmere and vicuña, has embraced the camel’s long-lashed relative.

Safe Designer Bets

No one does cashmere better than Loro Piana. The family-run Italian brand has been creating high-quality cashmere garments for more than 90 years. A cashmere turtleneck sweater can cost around $2,000; a baby cashmere peacock coat will cost around $7,500. Its alpaca products also hit the high end: A baby alpaca/wool blend coat can command $3,600.

Another Italian design maestro, Brunello Cucinelli, started selling sweaters out of his garage in the 1970s. His cashmere (and now also alpaca) garments rival Piana's in prestige, though style-wise, they have a more playful or funkier bent, often subtly trimmed with metal beads or sequins. An all-cashmere sweater will set you back at least $2K, and alpaca/wool jackets can fetch well over $5K.

The Bottom Line

How do you know which cashmere is the real deal? Even cheap cashmere can feel lovely to the touch, but rest assured, the poorer quality will mean it could pill or sag within days. Expensive cashmere will pill too, but that typically stops after the first wash. The best cashmere improves with age. Look for tension in knitting that “pings” the fabric back into shape and beware of anything suspiciously fluffy. (See also: Special Insurance for Designer Clothes).

Cashmere may have lost some of its exclusivity, but along the way it’s been joined by another fashionable fiber, alpaca, to keep you luxuriously warm. To guarantee the highest quality fabric, stick to established brands like Piana and Cucinelli, and steer clear of low-cost products if you want a garment that goes the distance. While the best clothing investments don’t come cheap, they can last a lifetime.

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