Design & components

Sleeping bag shapes


Mummy shaped bags

The Cocoon and Winter Lite are One Planet’s mummy-shaped bags, and the most thermally-efficient bags in our range. Designed to hug your body shape, these bags give the most warmth for their fill but have the least internal space. Winter Lite uses a combination of vertical and horizontal baffles, preventing the fill from shifting during use. The vertical chest baffles, which run from the neck to the waist, prevent the down from drifting from the highpoints of the bag (created by your torso) down to the sides of the bag during the night, causing cold spots. The baffles are also ‘sewn-off’, which prevents the fill from moving from the top to the base of the bag. However, this means the fill cannot be shifted as conditions dictate. Both the Winter Lite and the Cocoon have full-length zips down the side, allowing easy venting.


Tapered rectangular

The One Planet tapered rectangular bags provide a combination of efficiency and comfort, allowing more wriggle room and versatility but with an increase in size and weight. Most of our tapered rectangular bags use vertical chest baffles to keep the fill where it is needed. The Camp Lite uses V-shaped baffles. These are more efficient at preventing down movement than traditional horizontal baffles, but still allow down to be shifted within the bag to suit conditions.

The One Planet tapered rectangular range includes the Bungle, Bush Lite and Camp Lite down bags, as well as our synthetic range.


Rectangular bags

Rectangular bags are spacious and comfy, with the good old rectangle providing extra space for those who really like to move. Our versatile, cosmopolitan Robin Hoodless is designed for car-based camping or travelling where packed size and weight are less of an issue. In these conditions, there’s no need for a technical hood so we’ve removed it – the hood is a sleeve only, so a pillow can be inserted and will definitely stay put. V-shaped baffles help prevent the down from shifting unintentionally, whilst it can still be moved from top to bottom as conditions dictate. When unzipped, this style of bag makes a great queen-size doona: perfect for when you’re staying put for a while and want the comforts of home.


One Planet’s use of technical innovation and constant refinement to create exceptional products is demonstrated by our sleeping bag shells. We’ve devoted more than 30 years of designing and testing  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 use sewn-off box wall baffles. An air-permeable fabric that is extremely strong and lightweight is used to divide these baffles. This fabric also has one-way stretch to prevent 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. The baffles are also coated with tiny dots of silver which reflect heat back towards the user. Our bags are sewn with 13 stitches per inch, minimising fill leakage and increasing strength.

Vertical chest baffles

vert-chest-bafflesOur more technical bags use the One Planet vertical baffle system, designed to stop fill from shifting (intentionally or otherwise). 
This baffle system ensures the calculated amounts of down are kept in the correct areas, optimising the bags’ warmth-to weight-ratios. 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. Vertical baffles over the chest also prevent down from falling from the top to the bottom unintentionally during the night, causing cold spots.

Vertical chest baffles are used on the Bungle, Bush Lite, Cocoon, and Winter Lite bags, helping you to stay warm all night. (Either horizontal or V-baffles are used in other areas of the bag.) 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.

One Planet V-shaped baffle

V-shaped baffles are used on the Camp Lite, Cocoon and Robin Hoodless. 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. Over the course of two evenings, Dr Green took 800 paired temperature records, comparing the outside ambient temperature with the temperature inside the bag.


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. This kept the user up to 4.5 °C warmer than in the conventional bag.