All About Down | Everything you need to know

Going on a hike, planning an expedition or commuting during winter? Wherever and whatever the activity, the First Ascent Down range is your ideal companion. Down is nature's lightest and best form of insulation - warmer, lighter and more compact than any other insulation on the market. For years we have performance tested and improved our Down designs, continuing to mine Down’s unique properties, to deliver a range which suits every activity in any environment. 

What is Down?

Down, the layer of feathers found closest to a duck’s or geese’s body, is a natural insulator - considered the warmest, lightest and most popular insulator globally. Down insulation features a high warmth-to-weight ratio, trapping the body’s heat, and ensuring minimal heat loss. Down garments are extremely comfortable and versatile and have become the most sought-after garments when braving the winter chills.

What’s the difference between a Down and a Synthetic jacket?

Synthetic insulation is cheaper and easier to clean than Down, but it’s not as light or compressible. Down may be more expensive, but it has a greater warmth-to-weight ratio.

A Down jacket consists of an inner & an outer. The inner is duck Down or geese feathers that are perfectly engineered to insulate heat while being soft & quite literally, light as a feather! The secret to this insulation is ‘loft’. This might sound a little technical, but all it really means is that there are hundreds of little air pockets that trap & retain warm air, keeping you warm. 

How are Down jackets made?

Down jackets are constructed from a series of baffles - individual chambers which hold the Down in place to ensure even distribution of Down across the garment. Baffles are what give every Down jacket a different appearance. The Down, made of duck or goose feathers, is stuffed into the baffles, insulating heat.

First Ascent Glacier Jackets

How should my Down jacket fit?

Your jacket should not be too tight or too loose. The ideal is to have a jacket that fits snugly whilst still leaving enough room for layers. If too loose, cold air can get through and impact heat insulation. If it’s too tight it can be uncomfortable and restrict your movement. 

What is fill power?

Fill power is the international rating system used to measure the loft (fluffiness)  and the relative quality of the Down used in the garment. This number is calculated based on how much space one milliliter of a Down cluster takes up in a cylindrical tube.

Fill power can range from 550 to 900 fill; this number highlights the cluster size, which refers to the amount of body heat that the Down is able to trap relative to its loft. Fill Power does not determine the amount of Down utilized in a product, however the higher the loft the warmer it is.

First Ascent Glacier Jacket

What is Fill weight?

The fill weight of a garment refers to the amount of Down the garment holds, measured in grams. The more Down a garment holds, the warmer the garment will be. This reflects the weight of the garment.

What is Fill Ratio?

The fill ratio is an indicator representing the makeup between soft Down and harder feathers. A garment which features a higher percentage of soft Down, for example, 90/10, is a warmer, lighter and more easily compressible garment, as it features a high ratio of Down (90%) to feathers (10%).

Durable Water Repellent (DWR) Coated Down

Nothing can compare to the insulating properties of Down, however, Down naturally absorbs moisture, causing its insulating benefits to fall away. When moisture is absorbed into the Down fibres, Down filaments will stick together, creating gaps for cold air to penetrate and hot air to escape.

To lessen this effect, all First Ascent Down jackets feature a hydrophobic DWR coating, which aids in repelling water from the jacket's surface. Note that this coating does not make the jacket waterproof, and you would require an outer shell in order to wear it outside in rainy conditions.

Hypoallergenic Down

The majority of Down allergies which occur are the result of improperly cleaned Down. Down, being a natural product can be a breeding ground for dust mites, mould etc. which are the main cause of allergies arising.

At First Ascent we take great pride in ensuring that our Down surpasses all cleanliness tests to provide garments which are hypoallergenic.

First Ascent Glacier Jacket

Responsibly Sourced Down (RDS)

At First Ascent we are committed to developing garments which are designed and developed using fabrics and insulators which are ethically sourced, upholding our environmental responsibility and the welfare of animals. Duck Down is used across our Down Jacket range, as well as sleeping bags due to its high insulation properties and warmth-to-weight ratio. In 2017, we partnered with the International Textile Exchange, a body committed to minimising and reversing the negative impact of the Textile Industry on the environment.

All Down and feathers bearing the RDS logo are sourced from animals which have not been subjected to any harm, such as live plucking or force-feeding, giving fowls the freedom to roam around and live a free and healthy lifestyle.

RDS-certified Down provides us with a traceability platform within our supply chain, assisting us with tracking and validating the authenticity of Down from farm to the garment. Each step of our Down supply chain is certified by an approved third party, who ensures each farm/factory is audited and upholds the standards set by RDS.

Read more on RDS here:

Read our Guide to Down Jackets

Read about Caring for your Down Jacket.

Browse our Down Product Range