Cotton is a daily item in our lives. We sleep in it, we wear it, we even clean our ears with it. We use it constantly in one form or another, but there is a lot more to cotton than what we see on the surface. This section provides information on cotton-related terms that help you to go deeper in your understanding and make informed decisions for cotton comfort.
Where Cotton Comes From
A cotton plant produces flowers that turn into bolls. A cotton boll is the fruit of the cotton plant; it consists of fibers that grow around the seeds developing from the cotton flower. Depending on the species, the boll has hairy fibers of two kinds: long fibers called lint and short fibers strongly attached to seedcoat called fuzz. During production, the fibers of the boll are separated from the seeds and spun into yarn. Then yarn gets woven or knit into fabric.
Different cotton varieties are categorized by the length of their fibers, called the staple. Just like different people have short hair or long hair, different cotton bolls have short fibers (short-staple) or long fibers (long-staple).
The type or variety of cotton is determined by the genetic properties of the cotton plant and the conditions it grows in. Cotton thrives in sunny, hot conditions with fertile soil. Cotton, regardless of species, is considered a very durable material.
The most important characteristic of cotton is it's fiber length. Another consideration is the silky softness of the fibers. The longer the length of the fibers, the higher the quality. The higher the quality of the cotton, the more expensive it is.
Short-staple cotton (Gossypium herbaceum and Gossypium arboreum), includes cottons with a shorter length of 1/2 to 1 inch. This type is native to India and Eastern Asia.
Upland Cotton or Mexican Cotton (Gossypium hirsutum and Gossypium mexicanum), is the most widely planted species of cotton in the United States, constituting some 95% of all cotton production. Worldwide, the figure is about 90% of all production for this species.(2) Upland cotton comes in short-staple and medium staple varieties and varies in length from about 3/4 to 1 1/4 inches.(3) The species name includes "hirsutum" which comes from the Latin root hirsutus meaning rough, shaggy, bristly.(4) This could be because the leaves of this species are hirsute or because the cotton seeds are bristly and stick to the lint.
"American Upland Cotton was taken from Mexico to United States about 1700. During American Civil War, it was introduced into most tropical and subtropical countries of the world. It now forms basis of all commercial cotton crops of Africa outside the Nile Valley, all those of South America except in Peru and northern Brazil, of the modern Russian crop, and much of that of northern India and Pakistan, and the Philippine Islands, as well as that of the Cotton Belt of the United States. Upland and Cambodian varieties are invading the Chinese crop, and where these cottons are developed in southeast Asia, they will be based on these types and hybrids between them."(5)
Pima Cotton (Gossypium barbadense) "has a staple length of 1½ inches or longer, is produced predominantly in California, where it is particularly well adapted to environmental conditions. ELS cotton is also grown in the arid regions of southwest Texas, New Mexico, and Arizona."(6) Certain textile mills,manufacturers, and retailers are licensed by an organization of American Pima producers to use the brand name Supima, short for Superior Pima, for their products made from American ELS Pima cotton.
Sea Island Cotton or Creole Cotton or Peruvian Cotton (Gossypium barbadense) is a superior, very strong, extra long-staple [ELS] cotton of 1½ to 2½ inches that is grown on the islands just off the southeastern United States and in the West Indies.(7) It's fibers are silky smooth in strong contrast to Upland Cotton. The species descriptor barbadense refers to its perceived origins from Barbados, although there is controversy around the origins of this species.(8) This cotton is typically used for fine shirting fabrics.
Egyptian cotton (Gossypium barbadense) refers to long staple and extra long staple cotton grown in Egypt. All cotton grown in Egypt is "Egyptian" cotton. The best quality extra-long staple [ELS] cotton comes from the Nile valley regions. This cotton is favored for the luxury and upmarket brands worldwide. The extra-long staple Egyptian cotton can be made into very fine strong yarn. When woven, a strand of yarn is called a thread. The tiny-diameter fine yarn is what makes it possible to fit a high number of threads in an inch.
Many people believe that Egyptian cotton developed from Sea Island Cotton which is why it is labeled Gossypium barbadense; however, there are reports that Egyptian cotton came from an Ethiopian variety.(9)
The raw material from the cotton plant is made into fabric using different cotton processes. Some of these processes influence the comfort, durability, and softness of the end product.
The first process is called ginning which is done with a cotton gin. This is where the cotton fiber or cotton lint is separated from the seeds.
The raw cotton lint has fibers going in all directions. It costs less to use this lint as is, but a softer fabric results when this lint is combed. The combing process causes all the fibers go roughly in the same direction and it removes any shorter fibers. When you see "combed cotton" you know that the fabric is softer and more durable and less likely to pill. Items made from combed cotton, due to the extra processing step, are usually a bit more expensive than items from cotton that is not combed.
Another pre-spinning process that is sometimes done to cotton is to Mercerize the lint. The actual chemical structure of the cotton fiber is changed by first treating the raw cotton with sodium hydroxide (lye), and then with an acid bath. Mercerized cotton is very strong, since the chemical treatment causes the fibers to swell. Additionally, mercerized cotton cloth is easier to dye, is more resistant to mildew, and is shinier in appearance than other types of cotton. Mercerized cotton cloth tends not to shrink; however, cloth made from mercerized cotton picks up lint more easily than other types of cotton cloth. Mercerized cotton is most commonly used as a sewing thread.
Spinning is the process whereby the cotton lint is turned into a fine continuous thread or yarn. There are different industrial spinning processes. When you see the term "ringspun" it means that the cotton was spun using ring-frames in a continuous process that was developed in the 1829. Another type of spinning is mule spinning. The mule was the most common spinning machine from 1790 until about 1900 and was still used for fine yarns until the early 1980s. The most modern technique is called open end spinning. It was developed in Czechoslovakia in the years preceding 1967 and is much faster than ring spinning. These spinning processes vary in how much labor and time is used. Mule spinning can produce a finer yarn than ring spinning. Otherwise, the spinning process does not affect the softness or durability of the final fabric.
Cotton blend refers to the case where cotton fibers and other fibers such as polyester, rayon, linen, or silk are spun together into one yarn. In the case of polyester, this helps the manufacturer to have a lower cost of production. Often, short-staple cotton is blended with polyester for inexpensive fabric. In some cases, the a cotton-blend fabric will be stronger or have less wrinkles, but it will also be less comfortable, especially after the first few washings. A cotton/polyester blend often sets the stage for fibers to break away from the strand so that there is some furring (a tiny layer of fur from the fibers); the furring turns into pilling - little balls that form on the surface - and this progression leads to less comfort over time.
If you would like to learn more about cotton-related terms, the Cotton Inc. Textile Encyclopedia is a wonderful source of information.
Article by Sarah Seaver
(4) "hirsute." Dictionary.com Unabridged. Random House, Inc. 08 Jul. 2010. (Dictionary.com http://dictionary.reference.com/browse/hirsute).