如何挑选不易穿坏的毛衣：看懂纤维成分、纱线股数与养护要求

^{A version of the below was originally published in 2023.}

Hey, quick question: When did sweaters get so — for lack of a better word — bad?

The truth, it turns out, can be traced back to a high-volume, low-cost phenomenon that’s affecting multiple wardrobe categories, even those far beyond knitwear.

“Over the last decade, we’ve definitely seen a decline in quality across all price points,” says Andrea Cheong, creator and author of “Why Don’t I Have Anything To Wear?“. “A lot of it is affected by the rising cost of materials, but also the pressure for brands to keep increasing profits year on year, so what’s impacted are two key aspects that influence the quality of the final product: craftsmanship and materials.”

Yasha Morehouse, a professor of fashion at the Savannah College of Art and Design (SCAD), breaks it down even further. As consumer expectations for clothing are shifting, brands feel more comfortable subbing in less costly materials, like synthetic fibers, or just making fabric thinner, she argues. Unfortunately, sweaters, with their classically rich material makeup, have served as especially vulnerable subjects to this price-cutting experiment.

We feeble consumers are not entirely at a loss: We’ve tapped four knitwear experts to share the ins and outs of fabric content and how folks can best go about finding sweaters that won’t fall apart right now.

Why has the quality of knitwear declined so visibly?

In a word: synthetics.

These fibers, most often of the polyester or acrylic variety, are made from manufactured compounds that are produced when certain petroleum- or coal-based chemicals react with a variety of monomers, or small molecules like glucose, vinyl chloride or ethylene. (Yes, synthetics come from fossil fuels. According to data from the Fossil Fashion Campaign, synthetic fiber production uses the equivalent amount of oil per year as all of Spain, and polyester production alone produces as much emissions as 180 coal-fired power stations a year.)

But this dependence on synthetics in the knitwear industry is still a relatively new development. Dr. Imranul Islam, an assistant professor of textile development and marketing at the Fashion Institute of Technology (FIT) attributes the recent uptick to economic factors like lower disposable income following the pandemic and, of course, fast fashion. But Morehouse explains that even expensive brands are using materials like polyester and acrylic in the makeup of their knits, and it can be hard to find 100% wool or other natural fibers these days.

“I review endless new releases every week, from luxury to fast-fashion mall brands, and it’s becoming increasingly difficult to find items to recommend, mostly because most knitwear now has a synthetic blend,” says Cheong. “The ones that don’t aren’t always the quality I feel is responsible to recommend to customers, considering what I think is a far-too-inflated price point for a mass-produced item with unclear supply chains.”

What should you look for in terms of fabric makeup?

Well, no synthetics, for one — or, more reasonably, as few as you can find.

“Knitwear does not need to have synthetics in them,” says Cheong. “The cases where it may be understandable is where extremely fine materials, like alpaca or mohair, are used, but that begs the question: Why design an item that would need plastics to be durable just to hit a certain price point?”

Some apologists may argue that synthetics add stretch, which, supposedly, adds comfort. But Cheong notes that the nature of knitting already lends a degree of natural elasticity, simply because of the loops incorporated into the technique. Alex Josophiene, the Seattle-based creator of Alex Josophiene Knitwear, suggests focusing on a 100% natural wool product — specifically, “superfine” or “ultrafine” merino wool, the strands of which are finer than a human hair. It’s her favorite fiber to work with, as it’s softer and more durable than other kinds of wool.

Cheong advises shoppers to also look for certain details that premium knitwear brands tend to disclose, like ply, or the number of threads of yarn knitted together. A single-ply garment will be less durable (and less soft) than a two-ply one, where two threads of yarn have been twisted together to form the strand.

Finally, certifications exist to make this vetting process easier for the consumer, like the Responsible Wool Standard, the Responsible Mohair Standard or the Good Cashmere Standard, all of which require that farmers and ranchers meet animal welfare, land management and social requirements.

What makes a sweater more likely to pill?

Pilling is annoying, but all fabrics can do it. It’s simply caused by friction, which is why you may first see it under your arms or around your sleeves. But certain fibers — and the length of those fibers, known as the “staple” — may make pilling a more frequent occurrence.

“There are a few different reasons why a sweater pills,” says Morehouse. “One is that the fibers used to make the yarns are very short and ‘peel away’ from the yarn itself. Imagine braiding hair: If the hair is long, you’ll have a smooth braid; if the hair has shorter pieces in it, you’ll have lots of bits poking out of the braid, and those bits ball up into pills.”

When knitwear has been combined with synthetic fibers like polyester, the different lengths can also lead to more pilling. It’s basic chemistry, according to Morehouse: Synthetic fibers carry a negative charge, while skin and natural fibers have a positive charge. And while wool and cotton do pill, Josophiene explains that a larger percentage of synthetic fibers will significantly affect the longevity of the garment. Merino wool and cashmere, for example, are much less likely to pill over time, leaving a cleaner look and a better-quality sweater overall.

“Since acrylic and polyester have extremely low moisture content and low moisture regain, they’re extremely dry,” adds Islam. “They generate more static electricity than the fibers — like wool and other natural fibers — with high moisture content and moisture regain.”

Pilling can be prevented with proper care and maintenance. Always follow the washing instructions for your garments and store them properly, folding them without over-stacking them on shelves or in drawers (again, to mitigate that friction that causes pilling in the first place). You can remove pills just as easily, with a fabric shaver or even a disposable razor.

What’s the difference between cheap and expensive cashmere?

Cashmere, you may know, comes from goats. But what you may not know is that the word “cashmere” just refers to the goat’s fluffy undercoat, which grows to its longest length by mid-winter and sheds in early spring. Any goat (except an Angora goat) can grow cashmere, but the Cashmere Goat Association points out that what we call “cashmere goats” have been selectively bred to produce it in significant amounts.

“Cashmere as a name is highly protected,” adds Cheong. “To say that a garment is made of cashmere, the hairs used must be under 19 microns, which is the unit of measurement for the diameter. This is probably around what mass fashion uses.” Other fashion houses like Johnstons of Elgin, Barrie and “certainly the likes of Loro Piana” will use much finer hairs, sometimes as low as 14.5 microns, she says. This is called baby cashmere and can be experienced via the fabric’s “hand feel.”

Islam determines cashmere quality by three factors: fiber length, fiber diameter and the amount of crimping (or the waviness of the fiber). These characteristics make the yarn stronger and finer; they can also increase loft, a measure of how fabric interacts with air, which you’ll find more of in mohair or similarly fuzzy fibers. Cheap cashmere, however, may contain fibers from animals other than the cashmere goat (such as yak, llama or angora rabbit), or blend regular wool with the cashmere fibers.

Cashmere can also be broken down into three categories, dictated by the thickness of the fibers: Grade A is the softest, finest layer of hair, while grades B and C are coarser hairs, usually cheaper and not as soft.

Can you get a high-quality sweater without spending a fortune?

Yes, you can! Brands that focus on high-quality basics, like Uniqlo, have some great sweater options, says Morehouse. Just make sure to look for 100% natural fibers like merino wool, cashmere or even cotton. Still, it’s important to view knitwear as an investment: A great sweater will run you into the triple digits, but with proper care, it lasts for years, maybe decades, to come. 

Josophiene says it’s unlikely to find sweaters under $100 that have a 100% makeup of fibers like merino, cashmere or alpaca, but you can find some with a smaller percentage that still wear beautifully. “The key is making sure the majority of the makeup is natural,” she explains.

If you’re committed to staying under that $100 mark, look for 100% cotton sweaters, which tend to have a lower price point. Or shop secondhand, as vintage sweaters are frequently 100% wool or cashmere and have stood the test of time. But even then, Cheong says, don’t expect to snag fast-fashion prices.

“You definitely will expect to spend more than what fast fashion has normalized to get a good-quality sweater, but it’s essential for me to stress that, just because you may be able to afford the absolute best doesn’t always mean you need to,” she says. “There’s more to consider, such as whether you’re capable of taking care of such a valuable garment and if your lifestyle is suited to it.”

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