Cordura nylon fabric is commonly used for backpacks due to its durability, as backpacks often get tossed around and treated roughly. Kodra is a similar but even more durable fabric from Korea that is usually used for backpack bottoms. Backpacks were originally made of cotton canvas but this was prone to rotting over time. Nylon became the standard as it is lighter and more water resistant. Today's backpacks are often coated with PVC or polyurethane to make them waterproof, though this prevents breathing and can lead to mildew if the backpack isn't dried out regularly.

1. The Fabrics of Backpacks

2. The term backpack was coined in the United States in
the early part of the 20th century. They can also be
referred to as rucksacks, bodypack, bags, packs or
sacks. Backpacks were around before the 20th
century, of course. People have been carrying bags
on their backs since ancient times as carrying stuff
with your back is much easier than any other way.

3. Cordura is a brand name for the fabric that makes up
a large portion of the luggage in the world. You
probably know it as the "fabric on my backpack no
one ever bothered to think of a name for", but they
have and it's Cordura. Any typical backpack is
made from Cordura, a nylon fabric that was
invented by DuPont Chemical, originally for use in
military tires. Its greatest asset is its durability,
which is important for backpacks as they tend to be
treated roughly, tossed on the ground, and used in
games of catch by kids everywhere. Kodra is a
similar even more durable fabric from Korea,
usually used for bottom of backpacks.

4. Backpacks used to be made out of cotton canvas that
was given a wax coating to make it waterproof.
However, this presented a couple of problems. First
of all, the packs would be prone to rotting if stored
for a long period of time, a problem that was fixed
with the advent of nylon bags commonly seen
today. They were also terribly heavy, which is never
good for a carrying device.

5. Nylon is used now for backpacks nearly exclusively.
However, as waterproofing is almost always
necessary for backpacks these days, the nylon is
treated with a plastic containing PVC or
polyurethane that keeps all your possessions nice
and dry in your beautiful backpack. Coating fabrics
with PVC is very common for work clothing these
days and PVC fabric is cheaper than other forms of
waterproof materials.

6. There are upsides and downsides to waterproofing.
Waterproofing doesn't let your backpack breathe,
which means mildew can fester and ruin materials,
clothes, books, or anything else you carry in your
backpack. However, waterproofing allows you to
keep your materials dry in the first place, so as long
as you remember to air out your backpack
waterproof is probably the best way to go.
Backpacks have been around forever, its one idea
that's hard to really improve upon. However,
backpacks today are better than ever as they can
be made for whatever your needs are.

7. Resources:
http://www.rolishop.es
http://ezinearticles.com/?The-Fabrics-of-
Backpacks&id=7031831

8. Thank you for reading!