One Planet’s use of technical innovation and constant refinement to create exceptional products is exemplified by our sleeping bag shells. More than 30 years of design and testing has been devoted to developing the optimum sleeping bag shell.
The most important job of the shell is to keep the fill in position. This is done through a complex series of compartments called baffles: without these, the fill could move away from high points on the body, leaving you cold in the wee hours.
All One Planet down sleeping bags (except the Booster Bag series) use sewn-off box wall baffles made from Baffletex. This air-permeable fabric is extremely strong and lightweight, but it also has many other features. Baffletex’s one-way stretch prevents the baffle from tearing when stressed – it acts as a shock absorber within the bag, preventing baffle blow-outs and resulting damage to the bag. Our bags are sewn with 13 stitches per inch, minimising fill leakage and increasing strength.
Vertical chest baffles
Our more technical bags use the One Planet vertical baffle system, designed to stop fill from shifting (intentionally or otherwise). By incorporating a differential cut with a vertical baffle system, a series of radiating offset baffles are created, reducing baffle waste while keeping the down in the right place. (Either horizontal or V-baffles are used in other areas of the bag.)
Vertical chest baffles are used on the Bungle, Bush Lite, Cocoon, Winter Lite and Zephyr bags, helping you to stay warm all night. All baffles are also sewn off, further preventing fill movement. One Planet sleeping bags were the first in Australasia to sport this then revolutionary feature.
V-shaped baffles are used on the Booster, Camp Lite, Robin Hoodless and Stowaway. They keep the down in place more effectively than traditional horizontal baffles, making it harder for the fill to move unintentionally and cause cold spots. The down can still be shaken and padded from the top of the bag to the base to alter the insulation spread as conditions dictate.
Some years ago, Dr Ken Green of Berridale, NSW, performed an interesting experiment. To quantify the difference between V-shaped and conventional horizontal baffle systems, two sleeping bags were made, identical in fill and fabric. The only difference: one bag featured One Planet's V-shaped baffles, the other had conventional horizontal baffles.
Around midnight, the temperature in both bags was 31–35°C warmer than the ambient temperature. As the night wore on and the outside temperature fell, the bag with conventional baffles maintained this difference in temperature. However, as the pre-dawn minimum of -5.8°C approached, the bag with V-shaped baffles kept the user up to 39.5 °C warmer than the ambient temperature.
In other words, through the course of the night the V-shaped baffles prevented the fill from moving, keeping it where it was needed and the user up to 4.5 °C warmer than the conventional bag.