Down & Synthetic Fills

Filled to order

One Planet sleeping bags are hand-filled to order in our Melbourne factory, dramatically reducing the time each bag spends compressed in its stuff sack. (In contrast, our competitors’ bags are usually stored tightly squashed whilst in transit from Asia, then for who knows how long on the shelf.) We use complex filling charts to ensure the down is put in the areas where it is most needed.

Down fill

The quality of down in a sleeping bag makes a huge difference to the performance of the bag, in terms of warmth, weight, durability and compactness. However, often there is very little information provided about a bag’s fill, making it very hard to compare. We are the exception: read away!

What is Hydrophobic Down?

Down is the best insulation for lightweight camping gear due to its loft, compressibility and durability. However, this golden fibre has a failing: its ability to insulate drastically decreases when it is wet.

The solution is now here – Hydrophobic Down. This down has been selected to meet our rigorous standards, with a durable water-repellent (DWR) treatment applied after the cleaning and sorting process.

The benefits of Hydrophobic Down are:

  • It absorbs less water in damp conditions.
  • It retains higher loft (insulation) in damp conditions.
  • It dries faster.

Why does One Planet offer a choice between 700-750 and 800-850 loft down?

The answer is simple: to give our customers more choice regarding weight and price.
Want to save weight? Higher loft down provides better insulation so less filling is required, but it is more expensive. Want to save money? Lower loft down is cheaper, but more filling is required to achieve the same temperature rating. We leave the decision to you.

What is loft?

Loft is a measure of the ‘fluffiness’ of down – or, to be more scientific, the volume taken up by a given weight of down. The higher the loft (or fill power), the more air it will trap and the warmer it will be.

All our down is independently tested by the IDFL (International Down and Feather Laboratory), with the loft and quality of fill stated on the foot of each bag.

Duck or goose?

There is a widespread belief that down from a goose is better than that from a duck even though the performance characteristics are due to loft rather than the originating species. Why?

The roots of the misconception lie in the fact that until recently, the highest lofting duck down available in commercial quantities was 750 loft, so anything ‘loftier’ than this came from a goose. This led to the outdoors industry (including One Planet) promoting goose down as superior as the best insulating down came from geese. But now we can reliably source 800+ duck down and there is a new question: why pay more for goose when the performance is the same? (As an interesting side note, the highest performing down comes from the Eider duck.)

Temperature rating

All One Planet bags are temperature rated in accordance with ISO 23537-1, the international standard for sleeping bag performance. (This is the updated version of EN 13537.) The rating we use is the ‘limit of comfort’ rating, the lowest temperature at which a ‘standard’ man is able to have a comfortable night’s sleep.

Fill ratio

Most people move in their sleep, so loading the top of the bag with lots of extra down isn’t necessarily effective. We use a fill ratio of approximately 55/45, with 55 per cent of the fill in the top of the bag where it provides maximum warmth.

Ethically sourced down

Manufacturing at our Melbourne factory is good not only for quality control, product development, and ensuring durability and service, but also for the planet. However, we can’t run the whole supply chain, so take steps to ensure our suppliers meet certain standards.

Our down is ethically sourced, harvested and cleaned before purchase, with both the down and our supplier passing independent International Down and Feather Laboratory (IDFL) audits relating to ethical traceability. This means that the white down and feathers we purchase are from animals that haven’t been live plucked or force-fed at any point during the supply chain.

The IDFL has been around almost 40 years and has a solid base in China, from where around 75% of the global supply of down is sourced. There are more details on the IDFL here:

For more details on our other environmental policies and practices, visit
Please note: every One Planet down bag states the loft and quality of down used on the quality control label inside the foot of the bag. Our down may contain traces of down from species other than that noted on the tag. As down is a natural fibre, the quality may vary slightly from one shipment to the next. Minor adjustments in the weight of the sleeping bag may occur.

Thermolink Synthetic fill

Thermolink is fabulous. It gives us a massive 15 per cent increase in warmth (when tested to the European standard), meaning we can make our bags 200-300 grams lighter for the same warmth. The majority of this improvement is due to the fibre construction. Thermolink is a bonded fibre, with the fibre blanket linked throughout its thickness. This makes it strong and eliminates the need for sewn-through stitching and the accompanying heat loss.

Each One Planet synthetic bag has up to three layers of Thermolink, each with different properties. On the inside of the bag is a layer made up of smaller fibres; this contours to the body to minimise air pockets and maximise radiant retention and comfort. A thicker, more robust fibre layer on the outside of the bag gives better loft, reducing heat transfer through convection and conduction.

What you will notice about our new range is the things that are missing: the lines of stitching across the bags, and the extra weight and bulk you’re accustomed to with synthetics.