Nordisk, Black Yarn

Black Yarn Technology
Mixing Carbon particles into nylon fabric had never been done before in a sleeping bag, with the launch of the groundbreaking Black Yarn Technology. The advantages speak for themselves.
The combination of very stable and insulating black Carbon particles and nylon fibres create a fabric that accumulates the heat and detains it much longer than normal. This significantly slows down the cooling curve of the sleeping bag, adding an extra feature to the shell, since it no longer just encapsulates the filling, but also actively increases insulation.
The construction & combination of materials basically works as a 3 layer sandwich construction, with the Carbon particles in the middle creating a notable higher heat retention and at the same time easing the transportation of moisture out from sleeping bag.
Furthermore, the Carbon content provides a light sensitive feature to the fabric in which the fabric itself will charge and thus store heat from most light sources. Finally the Carbon/nylon mix strengthens the fabric creating a very durable shell.
Take a close look at Bering, and you will sense the black glow of the Carbon particles inside.