Fabrics--technically speaking fabrics are the result of constructed fibers. To understand the various characteristics of certain fabrics, it is necessary to understand fiber properties.

Cotton is a cellulosic fiber (plant derived) from the seedpod of the cotton plant. It is widely used for all apparel for its comfort characteristics. The comfort of cotton is due to its absorbency. When the body cools itself by sweating, absorbency is really crucial. It is highly uncomfortable feeling damp and sticky. Cotton absorbs the sweat and brings it away from the body allowing good evaporation of moisture, leaving the wearer in a state of comfort. Some less favorable but tolerable characteristics of cotton are that it wrinkles, shrinks, and is prone to yellowing when exposed to a lot of sunlight. Wrinkling is a common characteristic shared by many other fibers. Shrinkage can be minimalized by washing garments in cold water and drying at room temperature. Sunlight being harmful to cotton is only a concern with window treatments as they are exposed to sunlight constantly. Look for treated cotton or lightly dyed cotton where fading will be less noticeable. When shopping for cotton sheets thread count is important. The higher the thread count the softer, more durable the sheets will be.

Linen is a fabric made from the flax plant, and is considered the oldest fabric. The flax fibers are extracted from the stem of the plant by soaking the stalk in bacterial water or chemicals, a process called retting. This allows the fibers to separate from the tough outer stalk by a natural rotting process. Linen is used in a lot of summer time apparel for the same reason as cotton. It is even more absorbent than cotton and has the ability to dry faster and stay dry longer than cotton giving even more comfort to the wearer. A distinctive character of linen is its natural luster and somewhat irregular yarn appearance, seen especially when the fiber is plainly woven. This same appearance is copied with (imitation) 'linen' like fabrics usually made out of synthetic materials. It is also used to describe the texture of paper that is widely used for business cards and stationary. The only disadvantages of linen are that it wrinkles easily; shrinks and can break at areas that are repeatedly creased. This shouldn't be a grave concern as linen is the strongest of the natural plant fibers. Since linen is regarded as a luxury fabric, and is usually more expensive than most natural fibers it is recommended that it be hand washed or dry cleaned. This will ensure minimal shrinkage.

Hemp is another natural cellulosic fiber that has been gaining popularity in recent years despite its notoriety. Hemp has been around centuries as well and is quite similar to flax and thus very comfortable for wear during hot summer months. It is derived from the stalk of the male 'cannabis sativa' plant. It is the same plant that produces marijuana, but it is the female cannabis plant that produces the buds that are smoked. The cannabis that is grown for the production of hemp doesn't contain active ingredients. Hemp is really strong and used often for string and twine. Cannabis Sativa is an amazing plant that is easy to grow without pesticides. The oil extracted from the seeds of the plant is a good source of protein and can be used for food as well as cosmetics. The sad thing is that hemp isn't widely grown, because of political reasons. Wool is a protein fiber from the fleece of sheep that are usually sheared off once a year (clipped wool), without killing the animal. (Pulled wool is from an already dead sheep, and is of lesser quality.) It is one of the most versatile of the natural fibers, used all year round. In the winter, wool sweaters are invaluable for their insulating qualities. The fiber of wool has small scales around it that traps air giving it excellent insulating qualities. These microscopic scales are also responsible for the itchiness that some people experience with wool as well.

Wool is very absorbent and a bit water repellent due to the scales and natural oils that cover the fiber. Over time wool will get wet, but note that it has the ability to feel dry against the skin due to its excellent absorption qualities. This is the same reason why lightweight wool can be worn in the summertime. If fire is your concern, wool is flame resistant. It will not burn readily and will self extinguish when set afire, good to know when sitting a little too close to that fireplace or campfire. (Cotton, flax, hemp and rayon on the other hand will burn like paper.) As for care for your wool garments, they should be treated gently when hand washing and laid flat to dry. Wool will shrink in hot water and in the dryer so use cold water when washing by hand. Hanging them on hangers to dry will cause hanger shoulder (that annoying bump which sticks up from the shoulder). Dry cleaning is a good option and recommended for wool. Wool sweaters may sometime cause itching, due to the microscopic scales on each wool hair. Usually a finer (more expensive) wool such as merino or cashmere will lessen or stop the effect. Wool has also an annoying tendency to pill also due to the microscopic scales on the hair that tangles together. Use a pill comb and it should make your sweaters seem like new. I personally get annoyed at holes found in some of my nice sweaters due to moths and other insects, cedar wood blocks or balls will naturally ward of these pests.

There are many types of wool found from other sources. Merino wool from the Merino sheep, mohair from the Angora goat, angora from the Angora rabbit, camel hair from camels, cashmere from the Kashmir goat, and pashmina from the Tibetan Antelope.

Silk is another protein fiber made by the silk worm first cultivated by the Chinese centuries ago. The fiber is made by the silk worm by forcing a liquid out of two small holes in its head. Once the liquid is exposed to air it hardens. This long continuous strand sometimes reaching 1,600 yards is wound around the worm to make a cocoon. Before the worm turns into a moth the cocoons are heated to kill the worm. This is done to avoid the breaking of the cocoon that naturally occurs after the worm becomes a moth. Silk resulting from broken cocoons are not wasted, they are spun into yarn of lesser value and quality. Wild silk is made by wild or uncultivated silk worms that feed on leaves other than mulberry such as oak or cherry. This results in an uneven and textured filament. Cultivated silk worms live the good life, they are fed only young mulberry leaves. Silk is regarded as a luxury fiber due its 'hand' (feel), luster, drape, and dye retention. Silk takes dye really well and can be dyed in brilliant colors and prints. Silk is the thinnest of the natural fibers and is also very strong however, loses significant strength when wet. Silk can be hand washed with minor agitation or dry cleaned. It can be worn in the summer with comfort because it is absorbent as well as in the winter because it doesn't conduct heat away from the body. Silk also doesn't cause skin irritation the way wool might; In fact silk feels great next to the skin.

Manufactured--fabrics that are man made with synthetic ingredients.

Nylon is the first entirely synthetic fiber made in the U.S. by the Du Pont Company. It is desired for its lightweight, smoothness, durability and incredible strength. It is commonly used for seat belts, hosiery, and outerwear. Some of the less favorable common synthetic fiber characteristics that it possesses are, low absorbency, static problems and tendency to pill. Nylon is used for outerwear because, when woven finely it acts as a windbreaker and is waterproof. There are many types of manufactured nylons. Changes in filament shape, and construction often changes fabric properties, and thus end uses. A type of nylon created to compete with cotton widely used in active wear is Supplex. It boasts fast drying, great absorption and wicking properties (ability to pull sweat away from the body resulting in comfort).

Acetate is the second synthetic fabric to be manufactured in the U.S. and the first heat-sensitive fiber produced. It is mainly used for its aesthetic appeal as a low cost alternative to silk. It drapes well, is lustrous and doesn't yellow over time like silk. The tradeoffs for the favorable qualities are low strength, wrinkles easily, heat sensitive (will melt) and is prone to static. Acetone (nail polish remover) will dissolve acetate so keep clothes made of acetate away from it.

Polyester is the most widely used among the manufactured fibers. It is widely used in apparel because it allows for wash and wear, easy care. It is considered easy care because it can be machine washed, machine dried being resistant to shrinking and wrinkling. It is often blended with natural fibers (commonly cotton) to increase the ease of care of those fibers. Like nylon, polyester isn't absorbent (so you will feel like your wearing a plastic bag when you sweat); it also pills and is a victim of static. Fire and synthetics don't mix; synthetics will literally melt and stick to your skin if you are exposed to fire. You are better off with something that doesn't burn or burns quickly, characteristics of natural fibers.

Acrylic is used to imitate wool. Compared to wool it is stronger, washable, lightweight, non-allergenic and cheaper. It is often used instead of wool for sweaters, blankets and scarves. Although favorable for people with allergies to wool's itching characteristic, acrylic doesn't compare when it comes to wool's ability to absorb moisture, maintaining a wearer's comfort. Acrylic is also notorious for pilling. Sweaters made of acrylic won't be pill free for long, but price will offset the longevity of the sweater. Wool sweaters are an investment, while acrylic sweaters are disposable at the end of the season.

This concludes fabrics 101. There are many more fibers out there that I haven't covered. If you have any questions or contributions please feel free to e-mail me or post in the forums. I will get back to you as soon as I can.

Sources:

Kandolph, Sara J., Langford, Anna L., Hollen Norma, Saddler, Jane, Textiles, Macmillan, New York, 1993
Pizzuto's, J.J., Fabric Science , Fairchild, New York, 1994