Fabrics and insulation

Our experience has shown that improving the quality of fabrics greatly affects the overall performance of your sleeping bag. Helsport has developed a complete range of our own fabrics, specifically adapted for use in sleeping bags. By carefully selecting only the best fabrics suited to the intended use of the product, we’re able to ensure the comfort, durability and dependability demanded by the most serious outdoor adventurers.


Shell fabrics 

AIRTEX® 75D 100% POLYESTER DIAMOND RIPSTOP – durable, water resistant and comfortable shell fabric for TREK sleeping bags.

AIRTEX® 40D 100% POLYAMIDE DIAMOND RIPSTOP – lightweight, water resistant and durable polyamide used in PRO and X-TREM sleeping bags.

AIRTEX® 40D 100% POLYAMIDE DOBBY RIPSTOP – lightweight, water resistant and durable ripstop for PRO sleeping bags.

AIRTEX® 70D 100% POLYAMIDE RIPSTOP – robust and water resistant ripstop for X-TREM sleeping bags.

AIRTEX® 40D POLYAMIDE AND AIRTEX® 30D POLYAMIDE RIPSTOP – down proof and water resistant shell fabrics for down sleeping bags.

NO-SLIDE– A “no-slide” fabric which we use on the underside of selected models to stop the sleeping bag from sliding on the mattress. The material has a high water resistance and is highly durable.

Liner fabrics 

AIRTEX® 50D 100% MICRO POLYESTER – Water resistant and quick drying liner fabric that transports humidity out of the sleeping bag. Used on TREK, PRO and X-TREM segments.

AIRTEX® 100% POLYESTER 20D – extremely lightweight liner fabric which dries faster than traditional liner fabrics.

AIRTEX® 50D 100% POLYESTER – down proof liner fabric with good breathability and comfortable surface for down sleeping bags.


Fiber (Thermoguard®6000)

Helsport Thermoguard®6000 is a specially developed insulating fiber extremely well suited for sleeping bags. As insulation makes up the majority of a sleeping bag’s mass, developing our own high performance fiber has been critical to building lightweight sleeping bags with excellent warmth retention. Thermoguard®6000 is highly insulating yet has good loft and expansion, allowing us to use less material and produce sleeping bags with greatly reduced packed volume. Thermoguard®6000 is a blend of four-hole fibers and melted fibers. Melted fibres have a lower melting point than normal fibres and the insulation undergoes a special heat treatment that binds the fiber together and produces an even, stable insulating layer. This allows us to build Helsport sleeping bags with fewer seams than most others. Seams pinch the insulation fibers together creating a bridge that allows heat to escape while letting cold air in.

Thermoguard®6000 is also hypo-allergenic, water resistant and breathable making for a dryer, more comfortable rest. While we recommend washing at temperatures of 40°C, our sleeping bags can be washed up to 60°C if necessary.


We use only high quality down ensuring high loft and insulation for our users. We use a blend of goose down 90/10 (90% down, 10% feathers) with a fill power rating of 700 cuin/oz, ensuring good return to form after compression in our PRO and X-TREM sleeping bags.

We work with IDFL, the International Down and Feather Laboratory and Institute, in order to maintain the highest quality of our down blends, fabrics and construction of down sleeping bags.

The fabrics we use in our down sleeping bags are especially developed. They are down proof but still have a high breathability, which is important in order to get a good loft for the sleeping bag, and transport moisture from the body out of the bag. Some down leakage may occur with first time use, but will soon subside to insignificant amounts.

Down or fiber?

Down is a natural material with insulating levels that no synthetic fiber can match. Down offers premium insulation for low weight and small volume, which is the ideal for any sleeping bag. The major disadvantage with down is that its insulating properties can be greatly reduced if it becomes wet. A sleeping bag with fiber insulation however will retain more of its insulation value even if it becomes wet, and tends not to lost content if the shell fabric is torn.

Test partners


”IDFL is the global leader in quality assurance programs for filled textile products. We test, certify, inspect and manage quality assurance programs for companies around the globe. IDFL has tested thousands of filled textile products since its start in 1978 and is now the global authority on down and feather testing. We are proud to say that we serve over 4,000 clients in over seventy countries from our offices in Europe, China and the USA. Down and feather testing is a unique and difficult challenge, because down is a natural non-homogeneous product. Each test sample is handled individually so testing is very labor intensive. We test Helsport sleeping bags and garment fabrics for down-proofness during both their development process and production. We also test Helsport down blends for fill power, down percentages and general quality levels – all critical parameters to provide the very best down products to Helsport customers.”

Matt Lieber, Managing Director IDFL Europe


”Objective testing of sleeping bags by Thelma AS – now Thelma-Test – was started as a Sintef development project in the 1990’s with Helsport as one of our early industry partners. By means of a thermal manikin that simulated the heat production of a human being and a test laboratory where the thermal conditions could be controlled in an accurate way, the thermal insulation of sleeping bags was measured. Based on insulation values for men and women a model was developed to predict expected comfort levels for sleeping bags. In 2002 a new European standard (EN 13537) for sleeping bag testing was issued and Thelma calibrated their thermal manikin for testing according to this new standard. During the actual test, the manikin is placed inside a sleeping bag on top of an elevated wooden plate on an insulating mattress. The test is performed in a stable temperature atmosphere where also humidity and wind conditions are maintained stable, until the manikin’s “skin temperature” has stabilized at 34°C (+/- 0.1). Heat supplied to the manikin will then be similar to the heat loss from the manikin to the surrounding atmosphere. The final result is the average of three measurements and the recommended temperature limits are determined from this. Since 2002 Thelma-Test have tested more than two thousand sleeping bags from more than forty different manufacturers all over the world. In Europe today, similar testing according to EN 13537, are only performed at three other laboratories.”

Bård Holand, MSc at Thelma-Test