Down vs Synthetic Insulation

If you are planning on hiking in the Alps this summer, you will need to be prepared for all weather. You could be hiking in shorts and a t shirt in the morning and bracing yourself against wind and rain in the afternoon. Layers are a practical way to moderate your body temperature and a key component of the layering system is an insulated jacket.

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The first thing to decide when choosing an insulated jacket is whether you want a down or synthetic jacket. The choice depends on several factors:


Despite advances in technology, down is still warmer per gram than synthetic insulation. The higher the fill power of a down jacket, the warmer it will be for it’s weight and size. A 900 fill power jacket is much warmer than a 600 fill down jacket of the same weight. Higher fill jackets are often made of goose down as it has finer contruction than duck down and thus can trap more air. 

There is also a large range in the warmth of synthetic jackets depending on the type of synthetic fibre used. When it comes to insulation, you really do get what you pay for.


Down jackets pack down much smaller than synthetic jackets.

Performance in wet weather

In wet weather down clumps together and loses most of its insulation. It is also incredibly slow to dry. Whilst you can buy down jackets with a waterproof shell coating, they are heavier, bulkier and usually only used for more extreme conditions. 

In comparison, synthetic insulation is water resistant, stays warm when wet and dries much faster. Primaloft Gold for example holds 98% of it’s warmth when wet. Needless to say, it’s very popular in the UK!

Environmentally friendly

Primaloft is the market leading synthetic insulator and has transformed over 84 million plastic bottles into insulation. Their most innovative fabric to date is primaloft eco gold and uses 55% recycled products. 

If it’s eco friendly down you are looking for – Patagonia has a range of 100% recycled down products. Recycled down is reclaimed from cushions and bedding and works as good as new.

Ethical considerations

If you are going to buy down products, it’s important to ensure the down is sustainably sourced. In the past some down products were made from birds that had been force fed or live plucked. The outdoors industry is much more vigilent now and leading brands adhere to the responsible down standard


There isn’t a huge difference in price between synthetic and down jackets. The price of a down jacket depends on the fill power (high fill power being much warmer per gram and therefore more expensive). The price of a synthetic jacket depends on the type of material used. The best synthetic material on the market at the moment is primaloft gold. 


Synthetic jackets are undoubtably more durable than down jackets. Synthetic insulation is made of woven fibres and so if you tear your jacket, you won’t lose filling from the hole like you do with a down jacket.

Packing a down jacket into your pack over and over damanges the down and will cause it to lose it’s lofting power. Synthetic material does also lose it’s loft over time but at a slower rate. To make your insulated jacket last longer – keep it hung up, rather than packed inside a stuff sack. 

Which type of insulation for the Alps?

If warmth per gram is your key criteria then you can’t do better than down. However, if you are keen to reduce your environmental impact then synthetic jackets are the way forward. 

I personally keep a synthetic jacket in my pack when I’m hiking in the Alps. I like that I can use it no matter the weather and that it won’t complain too much about being stuffed in the bottom of my bag all season.

What’s your favourite insulated jacket? 

Jennifer Stretton
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