Down filled sleeping bags are a much more compact and lightweight alternative to sleeping bags with a synthetic fill. Down has many great properties that make it a wonderful insulation for sleeping bags but this does come with a price. Down offers the highest loft to weight ratio meaning that you will keep much warmer with much less filling than you would with standard synthetic filling. It achieves this by efficiently trapping warm air within the sleeping bag and providing much better insulation. Down filling can come in the form of duck down or goose down and they can be rated on their performance by fill power. 600+ is usually recommend as a high quality performance down sleeping bag and many of our Vango Venom down sleeping bags are filled with 700 fill power down meaning you know you can really trust the quality. The main reason to choose a down sleeping bag would be purely on the pack size and light weight that it can achieve. As it needs less filling, down can compress down much smaller than synthetic filling and will be much more lightweight. This makes them great for extreme adventures, hiking and mountaineering.
I have been looking for a pure cotton sleeping bag liner for a while but many brands say cotton but then it turns out to be polycotton. However this one from Lifeventure is 100% cotton like I wanted :-)
