How to make a sleeping bag warmer?
A sleeping bag liner is an essential element of your sleeping system when camping. It protects your sleeping bag and improves your sleeping comfort. A sleeping bag liner also offers a very soft and pleasant feeling in addition to providing additional thermal insulation.
Silk or cotton sleeping bag liners
Sleeping bag liners, which come in rectangular or mummy shapes to match your sleeping bag, are available in various materials, the two most common being cotton and silk.
Here are the advantages of each material:
Cotton sleeping bag liners
The most basic and cheapest. They absorb perspiration well and provide comfort at night. However, they are rather heavy (around 350 g in size regular) but very durable. A cotton sleeping bag liner will last years.
Silk sleeping bag liners
Silk offers softness and interesting thermoregulating properties. A silk sleeping bag liner will keep you warm in winter and fresh in summer. Silk is also very light and packable (around 110 g for a silk liner in size regular). The drawback being the price, silk is less affordable than cotton and less rugged. A silk liner can have a short lifespan, especially if you move around a lot during the night.
If you plan on camping often without covering great distances, a cotton liner will be perfect. On the other hand, if you are looking for maximum lightness for long backpacking trips, a silk liner will save you significant weight.
Which type of sleeping bag liner is best for thermal insulation, cotton, silk, fleece or thermolite?
While cotton and silk liners are the most common, nowadays you can also find warmer liners designed to camp in cold temperatures
Thermolite sleeping bag liners
This new material from Sea To Summit is made from hollow fibres which capture the air for more efficient insulation. The brand claims an increase of as much as 11 to 12°C degrees thanks to a Thermolite Reactor liner. (for a weight of around 260 g)
Fleece sleeping bag liners
Some brands offer fleece sleeping bag liners, designed for winter camping. Made of recycled polyester this material provides a real gain in terms of thermal comfort at night.
No matter the liner you choose, you can expect at least 2°C in addition to the insulation provided by your sleeping bag. If you plan on camping in winter, do not hesitate and opt for Thermolite or fleece for even more warmth.
Which liner to choose for trekking?
Generally speaking when it comes to trekking and backpacking, every gram counts. Silk liners are the best suited thanks to their unmatched lightness. Slightly heavy, silk and cotton mix liners offer the same thermoregulating properties as silk along with cotton’s durability. These mixed material liners may be heavier, but they will last longer.