The left side of this pair of jeans is made with Thermolite Infrared technology and has more red – meaning a greater thermal distribution – than the right, which is made with standard denim

The left side of this pair of jeans is made with Thermolite Infrared technology and has more red – meaning a greater thermal distribution – than the right, which is made with standard denim

Fibre producer Invista has developed two technologies under its Thermolite brand that offer new warming and insulating properties for jeans worn in colder climates.

The Thermolite Infrared and Thermolite Dual Layer technologies are the first offerings under a new brand category called Thermolite Pro. While they were revealed earlier this year, applications were initially aimed at the outdoor market.

But now Invista has applied them to denim fabrics, where they can be used independently or in tandem for enhanced warming and insulating properties.

The innovations "were driven by consumer research that showed that more than 70% of respondents were interested in the concept of a winter jean," says Jean Hegedus, global segment director for denim at Invista.

Denim fabrics made with Thermolite Infrared technology increase their temperature when exposed to solar or artificial light. Special ceramic pigments are added to the fibre that transfer the energy of infrared rays into heat the body can feel. For example, after three minutes under infrared light, surface temperatures of fabrics with infrared yarns increased two to four degrees Celsius, depending on the content of the infrared yarn in the fabric.

The patented Thermolite Dual Layer technology structure, meanwhile, creates open spaces within the fabric, trapping air to help keep the wearer warm. A fabric's ability to insulate is measured by its CLO value, and this new material can achieve CLO values that are typically 25% to 30% higher than standard denim fabrics, Invista says. The technology is also engineered to enable faster drying next to the skin, helping the wearer stay warm and dry.

Along with the new technologies, Invista is launching new imagery, hangtags, a new website, and promotional campaign for both its Thermolite and Coolmax brands, which emphasise the wearer's ability to be a part of the environment rather than fighting against it.