Tech: Down &
Synthetic Insulation

When you put on a down jacket or one with synthetic insulation, the thing that actually keeps you warm is air. Both down and synthetic insulation work in the same way: by trapping air molecules within the structure. The feathers or fibres themselves don’t hold any heat.

Basically, the thicker and more stable the insulation is, the more air can be trapped inside the garment, which means you’ll stay warmer in colder temperatures for longer.

The Mountain Studio uses both down and synthetic insulation in our different garments. Both technologies have their respective advantages, which means that the amount of insulation and warmth can be tailored to the conditions and intended use.

Although both down and synthetic insulation share many of the same properties, there are certain situations where one will outperform the other. Your choice will depend on the expected locations, activities, and conditions, or your own personal preference.

Down is the undercoating found beneath the exterior feathers of geese and ducks. It consists of clusters of light, fluffy filaments that grow from a central point.

These clusters of down trap air, and this air is actually what keeps you warm. Air is an incredibly efficient thermal barrier, unrivalled by any other material. The down’s volume is almost entirely filled with this trapped air, which makes down-filled garments both lightweight and compressible.

Baffles

Baffles are the pockets that are created between two layers of fabric, which hold the down fibres in place inside the garment.

Fill Power

Fill power, sometimes called loft, is a measure of the relative quality of down. The number is arrived at through a lab test that measures the number of cubic inches one ounce of the down (just under 30 grams) will fill.

In general, a higher fill power number indicates greater loft and more effective insulation. Broadly speaking, it’s a measure of how warm a jacket will be, although various factors, including how much down the garment contains, will affect its overall warmth.

Down Cluster Ratio

The amount of down vs. feather used to make the insulation mix in your down clothing. The higher the ratio, the more down the item contains, and the better warmth-to-weight ratio it will offer. For example, a down cluster ratio of 80:20 means that no more than 20% of the content is feathers.

RDS Down

RDS, or Responsible Down Standard, is an internationally accepted standard used to certify products made with feathers and down from certified farms. This means that the feathers and down used come from geese and ducks that have been raised in compliance with a set of principles and criteria for animal welfare. To earn the RDS label, 100% of the down in a garment has to be from certified sources.

Synthetic insulation is entirely man-made, typically crafted from polyester to form either sheets of wadding or lofted structures that mimic the properties of down. Filaments of various sizes are interwoven to create air pockets, which provide effective insulation against the cold.

This type of insulation is robust and durable, yet lightweight and quick-drying. It stays warm even when wet, making it particularly useful for high-intensity activities. When combined with highly breathable fabrics, synthetic sheet insulation adapts to your activity level and provides insulation or breathability as needed, regulating your temperature in a diverse set of conditions.

Primaloft

Primaloft® is a water-resistant, synthetic alternative to goose down that offers similar protection even in harsh conditions. The material is made from fine microfibre polyester fibres, which form small air pockets that trap the heat generated by the body.

Primaloft Gold® is one of the best synthetic insulations on the market. Being lightweight, water-resistant, and quick-drying, it’s the perfect choice for even the most challenging conditions.

G-Loft

G-Loft Eco EVOX is a synthetic insulation made from recycled polyester. It’s light, thin, stretchy, breathable, stays warm while wet, dries quickly, and combines the advantages of natural down with the durability of synthetic fibre. This makes it perfect for lightweight activewear like ski clothing.

Although both down and synthetic insulation share many of the same properties, there are certain situations where one will outperform the other. Your choice will depend on the expected locations, activities, and conditions, or your own personal preference.