Insulation Technology

Insulation Products

Keep the cold out with the latest insulated clothing.

Insulated clothing comes into its own in cold or chilly conditions, keeping you warm during cold evenings at camp, belaying in cold temperatures or on leisurely winter walks.


Most of the time, if you’re on the move, your body naturally produces more heat, but when you stop for a break your temperature can plummet.


To maintain your body temperature you need an insulating layer to create a barrier against the cold and retain your body heat.

Insulated clothing traps heat in tiny pockets of air close to the skin. The more hot air it traps, the better the garment and the warmer you will be.


Most garments will also enhance their ability to create a barrier against the cold with a durable water repellent treatment (DWR) on the outer fabric.

  • Creates a barrier against the cold
  • Retains body heat for longer
  • Good warmth to weight ratio

How It Works


The four main technologies are:

  • Down
  • Hydrophobic down
  • Synthetic
  • Fleece

Traditional Down


Down comes from geese and ducks, it’s the soft fluffy stuff beneath the outer feathers. With the greatest warmth to weight ratio, down traps air among lofting clusters, to keep you warm even under the most extreme conditions. The structure of these clusters means garments are lightweight and pack down well.


Down filled garments are the insulation choice for activities in cold, dry conditions. For down to remain warm and comfortable to wear it’s essential to keep it dry, as when it gets wet it loses its loft and most of its insulating properties. 



  • High warmth to weight ratio
  • Packs down well
  • High lofting capabilities

Hydrophobic Down


Hydrophobic down is a good choice for damp climates. This is regular down but treated with a hydrophobic (water-repelling) finish which helps it to withstand moisture sweat, dirt and other body oils. This finish helps the down to retain its loft even when wet, offering an excellent warmth to weight ratio in a wide range of conditions.


A durable water repellent (DWR) coating on the outer fabric helps to prevent moisture from penetrating through, further protecting the down from losing its loft and insulating ability. Keeping you and your kit warm and dry.



  • Resistance to moisture
  • High warmth to weight ratio
  • Packs down well

Fill Power Ratings


Down quality is measured in fill power, essentially this is how fluffy the down is. The fluffier it is the higher the fill power and the more warm air it can trap.


To measure fill power a cylinder is filled with down and a weighted disc is placed on top measuring the amount of space the down will fill when compressed. Manufacturers will also develop their own testing methods. These measurements are defined by the European Standard EN 12130.


Fill Power

  • 500 Fill power: standard quality
  • 600 Fill power: good quality
  • 700 Fill power: high quality
  • 800 Fill power: superior warmth and performance
  • 900+ Fill power: highest quality down available 




Synthetic insulation is ideal for cold, damp conditions. Made with fluffy clouds of polyester microfibres, it mimics the lofting ability of down, creating dense pockets of warm air.


These synthetic fibres are moisture resistant, retaining most of their insulating properties when faced with damp conditions, inside or outside the jacket. In persistently wet conditions however, all insulating garments should be protected by a waterproof layer.  



  • Maintains warmth when wet
  • Dries quickly
  • Easy to care for and maintain


Fleece is constructed with synthetic fibres that trap tiny air pockets and retain body heat. Whilst it can be highly breathable, the large pores in between the lofted fibres can let cold air in, so you may feel the chilling effects of the wind. Some fleece feature a windproof membrane in the lining, stopping cold air penetrating through the garment, keeping you toasty and warm. 


There are a variety of different fleece weights from 100 weight, a lightweight fleece great for active use in warmer weather, 200 weight, a mid-weight fleece for active in moderate temperatures, or 300 weight, a heavy weight fleece great for cold temperatures.  



  • Performs well under a waterproof shell
  • Can pack down well
  • Quick drying

Non Insulated Clothing

  • Retains less body heat
  • Cold air can get in
  • Can be heavy and bulky

If you’re outdoors in cold temperatures without insulated clothing your core body temperature can drop as the heat your body produces isn’t retained in air pockets close to the skin, instead it can escape through highly breathable garments.


Cold winds penetrating through fabric layers on a blustery day can draw heat away from the body and if you get wet you can lose heat up to 25 times quicker. In extremely cold conditions hypothermia and frostbite can be two of the biggest dangers.

Other Technologies

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