How is the filling in synthetic fibre sleeping bags constructed and attached?

The synthetic fibre insulation used in JACK WOLFSKIN sleeping bags is only sewn to the sides and to the lining in order to prevent thermal bridges. MICROGUARD consists of two different components, which are attached in different ways: the high-loft (MICRO) fibres in the lining provide optimal insulation, whilst the robust outer stabilising layer (GUARD) is only sewn to the outside side seam. This means that JACK WOLFSKIN MICROGUARD sleeping bags have no quilted seams on the outside.

Our current JACK WOLFSKIN sleeping bags feature THERMOZONE technology:
Additional layers of Microguard insulation partially protect areas most vulnerable to the cold (head, torso, feet).
This optimises heat retention and reduces weight. This is also adapted for the differing needs of men and women. The SMOOZIP –5 features additional fleece lining at the head, arms and feet.