Write your question hereHow many degrees...
Write your question hereHow many degrees do this add to a sleeping bag ?...
The average sleeping bag liner will add 10-15 degrees to your bag.
definitely less than that, maybe 5 degrees.
any liner will add some extra warmth to a sleeping bag, by virtue of the fact that it traps one more layer of air between the sleeper and the inner lining of the bag.
In the case of the woven liners (whether the Silk/Cotton blend as shown on this page, or the Premium Silk, or Cotton liners, that is the extent of the additional thermal performance they can offer, and indeed, a plus of 5° to 8° F (3° to 5°C) is realistic. The silk or silk/cotton blend liners may offer an additional performance edge in that they will wick moisture away from a sleeper, which prevents evaporative cooling.
If you want to add serious performance to a sleeping bag, we'd recommend the Sea to Summit Thermolite Reactor or Reactor Extreme, which will add up to 14°F/8°C for the Regular and 25°F/15°C for the Extreme. This performance comes from the fact that Thermolite is a hollow core fiber, and the liners have a 3-dimensional knitted structure, both of which trap air.
Please be aware, however, that the additional performance a liner can add is a function of your metabolism (whether you sleep warm or cold), of the external humidity, of the insulative value of your sleeping pad, and of the design/details of the sleeping bag itself. Given that there's no mandated standard for sleeping bag ratings, the performance claimed for *some* bags is somewhat unrealistic.
If you'd like more details, please feel free to contact me directly at firstname.lastname@example.org
Sea to Summit Consumer Relations Manager