Sleeping Bag Materials
Built to provide a restful slumber while enduring the
rigors of the elements and the great outdoors, the sleeping bags of today
are a radical departure from the simple cloth and cushions of old.
The modern sleeping bag is a precisely engineered construct
containing different materials that interact with each other to form an
excellent combination of warmth retention and comfort.
Each component of the sleeping bag serves a purpose, which it would
perform poorly if the wrong substance is used to craft it.
The outermost layer of the sleeping bag, known as the
shell, provides your primary defense against rain, wind, sleet and other
undesirable conditions. To
achieve this, the shell is commonly made from a synthetic fabric and coated
with a water repellent finish.
The threads are woven together very tight to prevent any liquids from
seeping through the fabric.
Nylon and polyester are the materials of choice, because their threads are
thicker than natural fabrics, giving them an edge in durability.
Polyester is heavier than nylon, but is superior in repelling water.
Certain brands of synthetic fiber are not as waterproof as others,
but compensate for this by providing additional breathability, so that the
user does not feel suffocated by the bag.
If the sleeping bag will not be used in damp locations, then
breathability is more important.
Some sleeping bag shells are made of cotton or flannel, but one should not
expect these bags to hold up well against inclement weather.
The meat of the sleeping bag is in its insulation, the
filling between the shell and the person that isolates and creates a pocket
of warmth, keeping the user’s temperature at a sleep-worthy constant.
For the best warmth to weight ratio, nothing beats natural down from
ducks or geese. Synthetic
insulation has not yet been invented that can match the effectiveness of
down, and as a result, sleeping bags filled with synthetic insulation tend
to be bulkier, heavier, and not as warm as their down counterparts.
There are a number of disadvantages to down filling, though.
If down gets wet, it looses its warmth-providing quality and becomes
twice as heavy. Worse, it takes
quite some time for down to finally dry out.
A good shell may minimize the chances of this happening, but when it
does, your sleeping bag will be practically useless.
Also, down is more expensive than synthetic material, so the
budget-conscious buyer may be willing to live with the compromise for the
right price.
Lastly, sleeping bags come with an interior lining, the
layer that makes contact with your body and clothes.
High-end bags will sport a silk or nylon taffeta lining that is
smooth and soft to touch and won’t catch on your clothing.
Less costly alternatives use a polyester cotton lining, which may not
be as comfortable. Sometimes,
lining fabrics will be treated to make them particularly slippery against
bare skin for added ease of movement.
Fleece liners can also be purchased separately, acting like blankets
to enhance the refreshing sleep that the sleeping bag provides.
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