Which Fabrics are most and which are least Environmentally Friendly?

Friendliest: "Natural Fabrics" are biodegradable

Made from Plants
Cotton is made from the Cotton plant. It also feels good on the skin, as it does not make you sweat. Cotton can be washed hot. It can last for years and years.
Linen is made from the Flax plant. Fabrics made from Linen get softer and more flowing with time. It does wrinkle easily when it is new, but when ironed looks great. It also feels good on the skin.
Hemp is made from the Hemp plant. It is very durable and can look beautiful. Usually fabrics made from Hemp are a little thicker.

Made by an Insect
Silk is created by the Silk Moth. It feels very soft and looks shiny. It cools in hot weather and heats in cold weather. It is very sensitive and can easily leave sweat spots. It can only be washed in cold water.

Made from Animal Hair
Wool is made from animal hair: Sheep, Goats, Lama... Wool warms in cold weather. It can be very soft or scratchy depending on the type of wool. If it just says Wool and is scratchy, it is probably made from Sheep hair.
  • Merino wool is a softer wool than regular sheep wool. It is made from certain types of sheep.
  • Cashmere is made from goats underbelly hair.
  • Alpaca is made from Alpaca hair.
  • Mohair is made from Goat hair.
  • Angora is made from Rabbit hair. However the Rabbits suffer greatly for it. Therefore I have stopped buying Angora altogether.

Less Friendly: "Natural Fiber Fabrics" are made with natural fibers, but use chemicals to create the Fabrics. (They are not as bad as synthetic fibers)

Rayon is made from wood pulp then mixed with Petrol. It feels good on the skin and drapes nicely. I find I can wash it cold and put it in the dryer and hang it up while still warm and then I don't have to iron it.
Viscose is similar to Rayon. It can be very flowy.
Bamboo is grounded to sawdust then mixed with Petrol.
Tencel is made from wood pulp (often Eucalyptus trees) and then chemically processed.
Modal is made from Beech Trees or Bamboo and then chemically processed.

Not Environmentally Friendly: "Synthetic Fiber Fabrics" are usually not biodegradable. Therefore they are not good for the environment.

Polyester's positive quality is that one doesn't need to iron it and it is often cheaper than natural Fabrics. However, it's look deteriorates after a few washes. One might sweat in it more than necessary.
Acrylic is often used in sweaters.
Nylon is used for fabrics that need to dry quickly like Parachutes, windbreakers, blouses. It is also very strong. Therefore fishing line is made of Nylon.
Spandex extends and goes back to it's original shape. It is used for tighter fitting clothes and in Swimwear. Often natural fiber fabrics have about 3% Spandex in them for the elasticity. Spandex is damaged by heat and light and therefore wears out after a while.
Acetate is used for inexpensive lining.