With its lustrous good looks, big price tag, and high-class appeal, silk is the very definition of luxury. But is it warm? Does silk’s function match up to its aesthetics, or is it just another case of style over substance?
Fortunately for anyone who’s just invested a small fortune in something new and silky, silk is a lot more than just a pretty face.
Does silk keep you warm? Silk with its softly draping texture forms an excellent insulating layer against the skin, keeping you toasty warm even as the temperatures start to sink.
Silk is a natural fiber, and as with most natural fibers, it’s excellent at keeping a warm layer of air next to your skin (although thanks to its breathability, it won’t end up making you feel hot and clammy in the way that synthetics sometimes can).
Silk has great temperature regulating qualities, meaning it will keep you at an even keel even as you transition from the warmth of indoors to the cold of outdoors.
If you’re looking for a fabric that will help you maintain a comfortable temperature, that’s lightweight enough to adapt to layering for extra warmth, and feels as soft as butter against the skin, silk won’t let you down.
Silk is something of a paradox, capable of keeping you cool in summer and warm in winter. The reason behind this almost magical ability comes down to its natural fibers, and specifically, to the ability of those fibers to regulate body temperature.
As the temperatures start to rise, silk disperses excess heat, leaving you feeling cool and fresh on even the hottest summer day. As the temperatures drop, silk provides an insulating layer between you and the chill, trapping in a pocket of warmth and keeping you toasty and comfortable.
Some fabrics might promise warmth, but the promise only holds good for as long as the weather does. Silk, on the other hand, will keep you warm even when wet.
If you’re an outdoor adventurer, silk makes a great base layer. Regardless of how drenched in sweat the silk becomes, its ability to absorb up to 30% of its own weight in moisture, while wicking away moisture at the same time, means that the sweat will stay locked away in its fiber, leaving you warm but not clammy.
Despite looking and feeling incredibly different, silk and wool actually have a lot in common. Both are made from animal sources (wool from the fur and coats of animals like sheep and goats, and silk from the cocoons of silkworms), and both provide a good layer of insulation and warmth. But for all their similarities, there can only be one winner when it comes to that big question – which is warmer?
And the winner is… wool. Silk comes for the cocoons of moths, a cold-blooded species that might need a dry, temperate environment when they’re in their larvae stage, but don’t need quite so much warmth and insulation as mountain goats, sheep, and the like.
Silk has its advantages, and in some cold-weather situations might even have the upper hand (after all, layers are key to keeping in the warmth, and silk, with its lightweight texture and easy drape, is one heck of a lot easier to layer than certain kinds of wool) but a wool jumper is still likely to keep you cozier and warmer than a silk blouse.
Cotton is many things. It’s durable, it’s easy to care for, it’s got great breathability, and it can be fashioned into just about any garment known to humankind. What it’s not is warm.
When it comes to keeping warm and toasty, the most important quality fabric has to offer is its ability to insulate. And (cotton-lovers, look away now) cotton is a terrible insulator.
Cotton has the ability to absorb a staggering 2500% of its own weight in water – great on hot, sweaty days, perhaps, but not so great in the cold. As soon as it becomes just a little bit damp, cotton will lose its insulating properties, and can even accelerate the cooling process, leading to a rapid conductive heat loss that might be great in the Caribbean, but not so great on a snowy mountain top.
To top it off, cotton has poor moisture-wicking properties (i.e. it absorbs moisture rather than wicking it away from the body) leading to long drying times and poor temperature regulation.
Silk, on the other hand, is known for its ability to regulate temperature. Although it can absorb up to 30% of its weight, it wicks away more moisture than it absorbs, maintaining its insulating powers and offering warmth even when damp.
When it comes to pure, unadulterated luxury, silk and cashmere are pretty evenly matched. But what about when it comes to warmth? Sure, you’re going to need a big wallet to kit yourself out in either one, but if you do (and assuming you’re heading off into arctic conditions), which is going to offer more bang for your buck?
Despite silk’s excellent heat-regulating properties, cashmere takes the prize. Made from the underbelly of the Mongolian goat, cashmere is exquisitely rare, sumptuously soft, horrifically expensive, and as warm as toast.
Compared to sheep’s wool, cashmere is eight times warmer – and like silk, it’s lightweight enough to be worn in layers, further compounding its heat-given properties.
Although be warned - it takes each Mongolian goat 4 years to shed enough hair to make just one sweater, which then needs to be sorted by hand, washed, and spun. Processing like that doesn’t come for cheap – and neither does that 100% cashmere sweater you’ve got your heart set on.
Silk and polyester might both be fabrics, but their similarities end there. While silk Is made from 100% natural fibers and has a reputation for exclusivity, polyester is a manmade fabric that’s nothing if not ubiquitous.
But what about when it comes to warmth? We know silk has great temperature regulating properties, but what about polyester?
Judging by how widely it’s used in base layer garments, not too badly. Polyester can be knit into a lightweight fabric that can be easily layered, while still possessing excellent durability. Unlike cotton (which, as you’ll remember, absorbs a tremendous amount of moisture), polyester absorbs only a tiny amount (0.4% of its own weight, in fact) and has great moisture-wicking capabilities.
All that being said, when it comes to a straight-out fight between polyester and silk, silk wins when it comes to warmth-to-weight-to-thickness, superior body-temperature regulation, moisture-wicking ability, and (a big plus if you’re planning on a long hike) odor resistance.
Silk and merino wool are both lightweight, all-natural fabrics, and possess very similar properties when it comes to body temperature regulation, moisture-wicking, and warmth-to-weight-to-thickness.
Like silk, merino wool is incredibly soft and can be worn comfortably next to the skin as an excellent base layer.
But, which is warmer? In fact, merino wool and silk are pretty evenly matched. Both absorb roughly the same amount of moisture (up to around 30% of their own weight) and both have hydrophobic qualities (meaning that the outer part of the fiber that’s in direct contact with your skin will wick away water rather than absorb it).
All in all, we’d have to call a draw.
Fleece is a type of synthetic fabric made from Polyethylene terephthalate (the same stuff that goes into plastic bottles, in case you were wondering). For most of us, fleece is synonymous with cozy, offering a warm, comfortable layer of protection against the cold.
But when push comes to shove, which will keep us warmer – silk or fleece? In a word, fleece.
In the same way as down, fleece traps your body heat in small packets, providing a gorgeously insulating effect that will keep you toasty even when the temperatures are dropping. By nature, it’s also hydrophobic, meaning it would far rather repel water than absorb it. While this might not be great for breathability, it is for warmth.
It may not have the same sumptuous elegance as silk, but if you want something to keep you warm in arctic conditions, fleece is going to be a better friend.
As anyone who lives in a part of the world plagued by long, hard winters knows, scarves are a cold-weather necessity. For most of us, wool scarves are the default choice... but let’s be honest, they’re not always the most elegant solution.
With their classical appeal and lightweight structure, silk scarves look more like fashion accessories than they do wind-blockers. But can they add more than just a touch of sartorial je ne sais quoi to an outfit? Can they keep our necks warm when the weather’s more arctic than the south of France?
Indeed, they can. Silk traps in heat, preventing any vital body heat escaping and keeping your neck as warm and cozy as you could wish.
It might not have quite the same insulating effects as fleece or cashmere, but have no doubt about it – a silk scarf isn’t just for show. Better still, it’s lightweight enough for you wrap it around yourself multiple times without feeling encased – and as everyone knows, there’s nothing like layers to beat the chill.
Do silk gloves keep your hands warm? Well, it really depends on just how cold the weather is.
If you’re heading on an arctic exploration of the North Pole, then no – a pair of silk gloves are unlikely to suffice. They might make the polar bears jealous of your style, but beyond that, they’re unlikely to do you much good. If, on the other hand, we’re talking a moderately cool day in autumn, they’re likely to do the job well enough.
That being said, silk gloves aren’t exactly a great way of protecting your fingers from frostbite. Silk may be warm and boast all kinds of awesome temperature regulating properties, but fingers tend to get icier than the rest of the body… and sadly, a silk glove just won’t cut it, at least on its own.
But that’s not to say silk doesn’t have a place in the glove world. When used as a tight-fitting inner liner to a larger outer glove, it provides a soft layer of warming goodness that perfectly complements the thicker outer shell.
Slipping on a pair of silk pajamas may be like slipping into a cloud, but what happens when the nights start getting colder? Will silk pajamas keep you toasty all night long, or will they leave you shivering beneath the duvet?
Fortunately, silk pajamas are just as cozy as they are stylish. Thanks to silk’s superior temperature regulating properties, they’ll keep you as cool as a cucumber in summer. In winter, they’ll keep you warm and cozy no matter how low the temperatures dip.
If you’re a camper, you’ll know that a sleeping bag isn’t always quite enough to keep you warm. And that’s where sleeping bag liners come so in handy. The extra layer of insulation they provide can make all the difference between a good night’s sleep, and a night where you’d wished you’d booked a hotel instead.
A silk liner doesn’t just keep your bag clean, it adds some much-needed warmth. Granted, there are warmer options (if you’re camping in very cold conditions, there’s no beating a thermal liner), but those looking for an option that will add some warmth while taking up minimal space in a backpack will find a silk liner a great choice.
Camping is all about traveling light. If you’re going to go to the effort of adding extra weight to your backpack, you’re going to want to know exactly what you’ll be getting in return.
In the case of a silk liner, you’ll be getting around 5° F of extra warmth. It may not sound much, but you’ll soon appreciate those extras degrees when the temperatures start to drop. Of course, it’s nothing compared to the +25°F you’ll get from a thermal synthetic layer, but considering a silk liner adds less than 200 grams to your gear, it still makes an excellent option.