Down jacket

What does down mean?:

Down is under-plumage of duck or goose.

It's different from feathers. Feathers have strong shaft and filaments coming out of it in flat structure. While down has a three dimensions, spherical structure, with filaments radiating from a central point.

It is found in between the skin and hard features of the duck or goose and protect the animal from cold (even freezing) water.

It is light and has good insulating properties because of large amount of small pockets of trapped air.

The name originates from:

1. Old Norse word dúnn meaning soft under feathers of birds
2. Which in middle english became doun
3. Which now has become down.

Properties:

Compared to synthetic puffer jacket, down jacket has following properties:

• Better Warmth to weight ratio. Measured as fill power which measure fluffiness / insulating air per ounce. Down jacket have fill power 400–900+.
• Loses loft and warmth when wet.
• Extremly compressible and light weight. Making it perfect for treks.
• Can last 10+ years when handeled with care.