Design and Tech


Down Certification

All Sea to Summit sleeping bags are sold with an International Down Feather Laboratory (IDFL) certificate that identifies the exact Fill Power of the down used.

UDD Beaker Comparison

We guarantee our sleeping bags are filled with premium down that exceeds the stated Fill Power in accordance to the International Down Feather Bureau (IDFB) standard.

- Repels moisture
– Retains loft
– Dries faster
– Anti-bacterial and anti-microbial
– Prolongs the life of your sleeping bag

In a world of technical brilliance it is remarkable that the performance of certain natural products have not been surpassed. Despite advances in modern fibre technology, down is still the best insulator warmth for weight, and is also the most durable sleeping bag insulation.

The problem with down is its vulnerability to water; moisture decreases the ability of the down to loft to its full potential and insulate, decreasing the warmth of your sleeping bag. Once down is damp or wet, it also takes a long time for it to dry out and effectively insulate again.

With the introduction of water-repellent ULTRA-DRY Down™ we have virtually eliminated the negative effects that moisture has on down. The ULTRA-DRY Down™ water-repellent treatment protects the down from external moisture and internal condensation.

ULTRA-DRY Down™ is a permanent* Nano-level water repellent polymer treatment applied to our high loft, high quality down. The Nano-thin treatment vastly improves our down’s reaction to water without effecting its weight or loft performance. ULTRA-DRY Down™ retains over 60% more loft and absorbs 30% less moisture when compared with untreated down. Sea to Summit sleeping bags dry out 60% faster than bags with untreated down.

The Nano-level treatment also inhibits bacterial and microbial growth, which makes Sea to Summit sleeping bags more hygienic and improves their lifespan.

Sea to Summit sleeping bags, using ULTRA-DRY Down™ in combination with our already formidable 2D- and 3D-NanoShell™ system give you the best chance of sleeping warm and dry, day in day out throughout the worst of conditions.

With these technologies combined there is simply no reason to choose any other insulation or shell for your sleeping bag.

*No loss of treatment effect has been seen in over 14 wash cycles.


Loft is the volume for a given weight of down. It is used to describe the quality of down, relating directly to the insulating performance. High loft down is warmer for a given weight than low loft down. Higher lofting down will fill a larger volume of space for a given weight. As a result, less down weight is required to fill each baffle in a sleeping bag. This translates to a lighter sleeping bag. The most common measure of loft is called Fill Power. 850 Fill Power implies that one ounce of this down will loft to fill a volume of 850in3.


850+ Loft Goose Down

850+ Fill Power (Loft) Premium Goose Down is the very best quality down available for sleeping bags. It provides the highest insulation for its weight and will last the longest.


650+ and 750+ Loft Premium Down

In the Sea to Summit Talus, Trek and Traveller series, our 750+ and 650+ Fill Power Premium duck down is a high quality insulation that sets the benchmark for sleeping bags in this class.