inexpensive children's clothing:Down Insulation

A common misconception is that down insulation is made from the feathers of a bird. Down is actually the plumage that’s found underneath the exterior feathers on waterfowl such as ducks and geese and consists of soft, fluffy, wispy filaments. Some products use a blend of down and feathers, but by definition, down is different than feathers.

Down insulates by trapping air and is prized for being light, easy to compress, long-lasting and breathable. It’s the insulation of choice in cold, dry conditions, or whenever reducing weight and saving space are top priorities.

Down insulation has typically been sourced from geese. However, many major manufacturers have recently made the transition to duck down throughout some or all their product lines due to the rising cost of goose down. All testing and performance standards are the same for duck down and goose down, so either way you can be assured you’re getting a high-quality product. However, you’ll find that goose down is often still used in the highest-end products because it is capable of reaching a higher fill-power rating than duck down.

Fill power is the term used to measure down’s ability to loft, and thus trap heat. It is calculated by how many cubic inches one ounce of down can fill in a testing device. For example, 600-fill-power down means that one ounce of that down fills 600 cubic inches of space. Premium goose down can reach 900 fill-power, and potentially even higher. Duck down can achieve fill-power ratings no higher than 750 or 800.

The advantage of higher-fill-power down is that sleeping bags and jackets require less down to fill space and achieve a certain temperature rating. Less down equals a lighter product. So a sleeping bag rated +20°F with 700-fill-power down will be lighter than a +20°F bag using 600-fill-power down (assuming the fabrics and other features are comparable in weight).

The most common criticism of down insulation is its tendency to clump up and lose loft when it gets wet, thereby losing its insulation properties. Within the last few years, proprietary technologies have been developed to treat down at a microscopic level with a water-resistant application. This treatment allows down to resist light moisture without compromising loft. However, if submerged in water or exposed to heavy rain, even treated down will get wet, so do your best to keep your down-filled items dry.

Pros

Higher warmth-to-weight ratio than synthetic insulation

Very compressible

Very durable; with proper care, a down sleeping bag or jacket can last for decades

Cons

Loses insulating power when it gets wet and takes a long time to dry

Cleaning down requires special care

Not hypoallergenic (rarely an issue)

More expensive than synthetics