Synthetic insulation is possibly one of the most versatile pieces of garments you can own. A synthetic jacket is designed to be the alternative or in between a fleece jacket or a Down Jacket. The bonus of this type of garment is that it can get wet and will not cause any harm to the inner filling, whereas a down jacket when wet does not perform. It can be worn as an insulated inner layer beneath your waterproof jacket; It can be worn also over the top of the waterproof jacket when you stop for lunch as an insulated layer. Allot of climbers use this time of jacket as they perform better than a Down jacket or fleece when in alpine or mountain conditions.
What to look for: If you look at the higher specification jacket that use a Primaloft insulation, these jackets are designed to be used and a abused. The inner fibres are designed not to break down easily, especially when stuffing them and taking them out of a rucksack constantly. A cheaper non branded equivalent although will keep you as warm, will break down quicker, but is perfect for wearing as a general walker or keeping warm camping etc.
With a wide range of down jacket, choosing the warmest or the most suitable one can be long winded, So let’s take a look at what you need to look for to find out which one is best for you.
Down jackets are fantastic as they will generally last 3 times longer than synthetic jackets. But the downside to down is that it will lose thermal properties when wet. Therefore they are perfect for when it is a bitterly cold dry day.
Down comes in many different forms and quality of feathers. The easiest is to look at the Fill power of a down jacket. The fill power of a jacket explains how much loft the down has. So the higher the loft the warmer you will be for less weight of down. Therefore if you choose a jacket that has between 500+ - 600+ this is perfect suited for everyday use, keeping warm on way to work etc. If you choose something of 700+ or more then these are more suited to mountain use keeping you warmer at colder temperatures. The Fill power will also show you how much loft is in a jacket so the higher the loft the smaller the jacket will packed down if it need to go into a rucksack or similar. Where as a lower spec although will be warm enough will be big and bulky when packed.
Next you can compare how much weight of down is in the jacket the more you have the warmer you will be. This is easier to compare when you choose a jacket with the same fill power of down to tell which one is warmer.