Down is a unique and exceptional form of insulation. It has the best insulation value of any filling known relative to its weight and compressibility. It is also remarkably resilient and, unless physically or chemically damaged, can return to its original form no matter how many times it is twisted or compressed.

Made from a protein called Keratin it is very similar to human hair and comes from the soft plumage of waterfowl (Ducks & Geese). Consisting of light fluffy filaments growing from a core it typically accounts for less than 20% of the actual feather mix from a bird (around 100 grams of useable down will be obtained from a typical Goose) and will always be mixed with small amounts of feather. Consequently all down fills used are a mixture of down clusters and small feather with the highest of percentages of down relative to feather giving the best performance.

Since we first began producing down clothing and sleeping bags we have always sourced both high quality goose and duck down for use in our products. Whilst Goose down of the highest quality is proven to offer the very best performance, all of the testing we and other independent laboratories and down wholesalers have done has shown beyond doubt that the very highest qualities of duck down easily surpass the performance of lower quality goose downs.

Irrespective of which type of waterfowl down is sourced from, its ability to loft is primarily affected by its size and condition. The maturity of the bird and the conditions and climate it experiences contribute significantly to the quality of its down, only if all other things are equal does the type of bird then matter. By choosing to use more mature Ducks from the Northern regions of China as well as Geese from the Ukraine in Eastern Europe we are able to control the quality of the down we use and consistently guarantee its performance.

Each and every batch of down we use is independently tested by the International down & feather laboratory (IDFL) in Zurich. Testing is done to certify its species of origin; its down cluster and feather purity and of course to measure its ability to loft since it is this which ultimately affects how well it is able to insulate. This measurement of loft is called its fill power.

Like human hair, down has a structural memory that changes according to the conditions and environment which it is in. It’s this three-dimensional structure which makes it such an effective insulator, but its compressibility and ability to change according to its environment mean that accurate testing is notoriously difficult.

Over the past forty to fifty years various methods have been developed to measure fill. Contrary to popular myth there is now only one single recommended test for fill-power performance. The days of having to question whether down has been tested to US, EU or EN standards or making ad-hoc and often inaccurate calculations to try and convert numbers between manufacturers should be a thing of the past. There is now only one internationally (IDFB) recommended test – the Lorch Cylinder Test and one recommended preconditioning method - steam.

Mountain Equipment was an early adopter of this revised standard and for the past five years all our testing has been done according to this method. In addition to that we have consistently chosen to advertise guaranteed minimum standards of fill power performance. Following a 3 year period of achieving consistently well-above advertised performances with the down we source we are now amending our advertised fill-power ratings so that they better reflect the quality of the product you are actually buying.

850 Fill Power Goose Down

Our very best Eastern European goose down. Sourced from the Ukraine, with an actual minimum down cluster content of 93% * and individually tested both to ensure a minimum fill power of 850 cubic inches and be DOWN CODEX™ approved.

* For legal reasons this is stated as minimum content of 90% in the USA.

725 Fill Power Duck Down

Our premium duck down. Sourced from Northern China, with an actual minimum down cluster content of 90% and individually tested both to ensure a minimum fill power of 725 cubic inches and be DOWN CODEX™ approved.

725 Fill Power Water Resistant Duck Down

A high-quality duck-down, sourced from China with an actual minimum down cluster content of 90% that has been treated with a water-repellent Bluesign™ approved Teflon treatment to allow the down filaments to resist moisture and dry faster

625 Fill Power Water Resistant Duck Down

A quality duck-down, sourced from China with an actual minimum down cluster content of 80% that has been treated with a water-repellent Bluesign™ approved Teflon treatment to allow the down filaments to resist moisture and dry faster.

Polarloft Micro

POLARLOFT Micro is an advanced synthetic insulation. Made from a combination of 3D long filament fibres and micro fibres it gives excellent warmth with low weight and small pack size. Fast drying and almost unaffected by wet conditions it is ideal for a range of mountain and valley uses.