Odds are, you are wearing something made of cotton as you read this. Cotton is the most widely used natural fiber for making clothing because it is soft and comfortable, has good absorbency, and conducts heat well. Cotton is one of the few breathable fabrics, so it is ideal for both hot summer days (the fibers wick perspiration from the body) and cold winter days (cotton helps retain body heat). It is used in a variety of forms, including denim, khaki, gabardine, and sateen.
Cotton has an interesting history and some surprising characteristics.
- Cotton is stronger when wet
While other cellulosic fibers (rayon, wood pulp) lose strength when wet, cotton becomes stronger when wet. The hydrogen atoms in water create extra bonds with the cellulose in cotton, increasing the strength of the cotton.
- Cotton has been used for over 7,000 years
Scientists found bits of cotton bolls and pieces of cotton cloth at least 7,000 years old in Mexico. In Pakistan, cotton was being grown, spun, and woven into cloth around 3,000 BC. Arab merchants brought cotton cloth to Europe about 800 AD. By 1500, cotton was known throughout the world.
- There are 50 different natural species of cotton
There are 50 cotton species, but only four have been domesticated for their fiber. These four varieties are the only ones that have the fiber length or oil content levels that justify large scale cultivation and processing. Two are from the Americas, one from southern Africa and one from India. Cotton derived from Gossypium hirsutum accounts for about 90% of all cotton production.
- Cotton plants produce fruit
Once a cotton plant flowers and is pollinated, it produces a fruit called a boll. The boll is a hard capsule with fiber and seeds inside. When the fruit is ripe, the boll splits open revealing the fluffy stuff we know as cotton. Cotton flowers are also quite beautiful.
- Most banknotes are made using cotton
Many people think banknotes (money) are made of paper. In fact, if banknotes were made with paper, you wouldn’t be able to use the notes if they got wet. Most countries use cotton for making banknotes, including the USA which uses a mixture of 75 percent cotton and 25 percent linen to make cash.
- Cotton was the first plant to grow on the moon
The Chinese spacecraft Chang’e 4 took cotton seeds to the far side of the moon. According to China, cottonseed from that batch sprouted in January 2019 inside the spacecraft in the Von Kármán Crater of the moon. Sadly, the plants died from the cold of the moon shortly afterwards.
When you pull a tee shirt over your head, dry yourself with a warm cotton towel, or put on your favorite pair of jeans, take a moment to reflect on how amazing cotton is. For over 7,000 years, humans have been using cotton to keep warm, or stay cool, or just feel comfortable.