Sourcing down jackets? Here's what you need to know.

Abrupt changes in weather patterns, resulting in colder climate and prolonged winter, especially in many regions in North America and Europe, along with increasing interest in winter sports have driven the popularity of down jackets in recent years.

Analysts believe this upward trend will continue in the next few years with global outdoor apparel sales expected to hit $94.5 billion by 2021. Revenue from down jackets is predicted to post double-digit growth during the period.

In line with this, international product testing and certification body released recently a guide to help manufacturers and consumers identify what makes a down jacket effective.

The group gave a detailed description of how the type of filling or insulation and product design affect the ability of a jacket to provide warmth, what shell materials and quilting methods are popular, and the various treatments and finishes applied to enhance heat-retention and breathability.

In China, high-end models use duck or goose down and feather for the filling with ratios of 80:20 or 90:10. Some adopt 100 percent down but these are limited to the most expensive pieces. Several suppliers also utilize synthetic alternatives such as microfiber. While not as costly, artificial variants are said to have the warming capability similar to or even greater than natural down.

A number of makers are exploring sustainable alternatives like this model, which features biodegradable plant-derived filling. This jacket, meanwhile, comes with a core made of the increasingly popular wonder material graphene. The garment is said to convert energy from light into heat.

Several major brands are also incorporating social consciousness in their choice of material. Sweden-based fashion brand H&M and outdoor apparel giant The North Face have begun using responsibly sourced down exclusively for their releases.

As regards shell material, nylon and polyester are top options as the fabrics are strong enough to withstand harsh conditions. These are also treated for enhanced breathability and water-resistance as trapped sweat and wet downdecrease the ability of a jacket to provide heat.

Even the construction is done with optimal heat-retention in mind. Hoods, pockets and zippers are designed to give wearers maximum warmth more than visual appeal.

Down jackets have become a garment of choice in places with cold climate. In some regions with freezing weather, these are essential for survival, making choosing the right down jacket an extremely important decision.