Different fabrics have different properties, depending on what they’re made of. This means that clothing designed as an outer layer will be made of a different fabric to a base layer. This choice is often determined by things like the weight of the fabric, how insulating it is, and whether it’s waterproof.

No good using denim as a winter coat when you’re expecting rain and snow; it can be heavy and uncomfortable when wet and is slow drying. Maybe a reason not to choose jeans for your winter bottoms, even if they seem like a thick layer to cut out the wind chill.

So if you’re looking for the warmest winter fabrics for your bottom half, take a look at some of these:

Wool is naturally insulating, designed to keep sheep warm in its original form, and nicely moisture wicking. So it’s great for keeping you toasty warm without getting too sweaty. It’s naturally water resistant and therefore shower-proof. If it does get soaked, it can take a bit to dry out, but it makes a brilliant layer of protection between you and the cold.

Wool is also incredibly versatile, allowing it to be used for many different types of clothing, from socks to leggings to jumpers and coats. We’re a particular fan of merino wool because it’s also more lightweight and extra breathable, as well as naturally anti-bacterial and anti-odor.

While it doesn’t work well as a top layer, because it doesn’t like rough weather, silk can be a great insulating material. Using it as an under layer can help keep you warm without getting too sweaty.

Silk is lightweight, breathable and very insulating. We at New Zealand Natural Clothing like to blend it with merino wool to help take advantage of the similar properties of the two fabrics.

Down is a brilliant insulator. It is made from the soft feathers of ducks and geese and often stuffed into waterproof coats or used in sleeping bags.

This waterproofing layer is necessary because the feathers don’t have natural waterproofing of their own, that’s normally on the harder outer layer of feathers on the goose or duck. The downy feathers trap air heated by the body as a warm layer between the wearer and the cold air around them.

It’s a natural product, but often more expensive because it needs to be carefully gathered from the birds themselves. In terms of trousers and winter bottoms, down is mostly to be used as part of a winter activity outfit, such as a ski suit, for when you’re expecting more extreme temperatures for longer periods of time.

A lot of mammals use their natural fur coats to keep themselves warm. It can work just as well for people. Fur traps air between each hair, much like down does between feathers, and this allows body heat to warm that air and use it as a buffer against the colder air outside.

Similar to a wetsuit but with air instead of water. So having a fur or faux fur trim on your hood, or on the edges of your gloves and boots, can help trap warmer air and prevent a frosty nip to your nose, fingers and toes.

Thicker cottons can definitely keep you warm. Cotton may be associated with thin summer clothing because cotton is lightweight and breathable, but it can be a great winter choice too. When made into a thicker fabric, cotton might be a better winter material if you have a wool or fleece allergy and so need to avoid more common winter weather layers.

Cotton does absorb water, so might be best to wear under a waterproof layer if you are going out in the wet.

Hemp fibres are a natural plant based, highly insulating material. It also has natural anti-bacterial and anti-microbial properties, and is sometimes used by those with sensitive skin as it is very soft and gentle on the skin.

It can be a great choice if you want to avoid animal based fabrics, and is still breathable and lightweight similar to wool.

Fleece is a synthetic fabric, made of polyester and designed to mimic the properties of wool. So it’s warm and lightweight, but doesn’t hold water in the same way as wool so it dries much faster. This can be very useful in damp or snowy conditions.

Fleece doesn’t have the same natural anti-bacterial or anti-odor properties as wool though so it might need washing more often. It’s not often used as the sole fabric for trousers, but it is a great choice for a lining on thick snow trousers or in coats.

Another synthetic fabric, nylon is great for waterproofing, but not the best for warmth. It can help keep some of the wind chill off but it’s not insulating against the cold air all around you.

It’s thin and lightweight, and is often the material used for umbrellas and packable or ‘stuffable’ waterproof coats.

Corduroy is a soft and comfortable fabric, often used for trousers and jackets. It is thick and tough to keep out cold but not rough on the skin.

A great choice for trousers, especially if your other option was denim jeans, which are very water absorbent and slow to dry.

Obviously, not all winter days are snowy, fun days outdoors. Life and work don’t stop just because the days are shorter and the weather is colder. Dressing in winter is all about combining comfort, style, and mobility with warmth and weather proofing.

Work days mean you need to look smarter but still want to stay warm. Perhaps consider swapping to a wool suit instead of cotton, or wearing warm woolen tights under your skirt. This can apply to formal events too. And obviously, base layers are great, whether that’s an undershirt or vest, leggings or tights, or simply snugger socks. They can be a good way to keep warm without affecting your external appearance.

If you want to be out and active, keeping up some exercise despite the season, you will need some winter workout clothing. Wearing leggings gives you more mobility than trousers, and you might want to consider using specific warm socks for your activity, whether that’s hiking, running or skiing, to keep your toes toasty warm and still prevent blisters caused by rubbing. That’s not to say we should be ignoring the usual hats, gloves and scarves of course.

Lounging at home should be warm and comfortable too. Perhaps you could save a little on your heating bill by getting some warmer wool lounge trousers, or leggings. There are also options for lightweight sweaters or long sleeved tops in warm materials like merino wool or thick cotton. And let’s not forget warm and snug socks. Maybe some fluffy ones, just for fun.