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Determining the Quality of Cotton

Assessing the quality of cotton is complicated because like snowflakes, every cotton fiber is unique with varying lengths, widths, thickness and shape. The U.S. cotton industry together with the USDA and other cotton growing countries are continually reviewing and improving the methods for classing cotton.

The first standardized system for determining the quality of cotton was created by the U.S. Department of Agriculture in the early 1900's. In 1923 the USDA together with 21 other countries created the Universal Cotton Standards Agreement establishing a uniform criteria for classing cotton. Since then the group has met every 2 or 3 years to review the standards and methods for testing cotton.

The grade of a cotton bale is based on fiber length, uniformity, strength, fineness, color, and trash (leaf, bark or other non lint material). There are two species of cotton used for textile production; Gossypium hirsutum and Gossypium barbadense. Each has its own classification criteria.

Today over 95% of the cotton used in textiles is from the Gossypium hirsutum species, more commonly known as 'Upland Cotton.’ The varieties created from Gossypium barbadense are known as Extra Long Staple.

A bit of the history….

"100% Egyptian Cotton" conjours up an image of the ultimate luxury.  Pima Cotton is known for its exceptional quality.  Are these claims true or marketing hype?  To know where the hype stops and the truth begins, we need to know a little history.

Egyptian cotton and Pima cotton are actually closely related, both have their roots in Sea Island Cotton.  In the late 1700s most of the cotton grown in the U.S. was Black Seed Cotton or Sea Island Cotton. Both varieties were extra long staple (ELS) that thrived in the coastal areas of the Southeastern United States. Upland cotton, which could only be grown further inland,had a shorter growing period than ELS varieties. The downside was the seeds that needed to be removed by hand. It took one person about 16 months to remove the seeds from 500pounds of cotton. Although the cotton was grown in the American South and the work was done by slaves, Upland Cotton was not economical. (note 1)

Then in 1793 along came Eli Whitney. His invention of the cotton gin transformed the cotton industry and the South by making the production of Upland Cotton profitable. Prior to the invention of the cotton gin, exports of Upland cotton were less than 500,000 pounds per year. Between 1793 and 1800 exports increased to 18 million pounds per year and by 1820 exports were up to a whopping 128 million pounds per year. (note 2) Accounted for over half the United States’ exports, cotton was proclaimed 'king' in the American South.

Cotton production plummeted during the American Civil War.  The Northern States blockaded the South effectively cutting off trade with major export markets.  The exponential increases in cotton production ground to a halt. The South would not reach its prewar record of cotton production until 10 years after the end of the Civil War.

Britain and Europe turned to the East, particularly Egypt for an alternative source.  An article in the NY Times dated June 26, 1864 reported the incredible development of a new ELS cotton variety in Egypt known as Jumel cotton. Prior to the Civil War, Egypt exported only 500,000 cantars (a cantar is roughly equivalent to 50 kilos). In 1861 exports increased to 600,000 cantars and by 1863they had more than doubled to 1,287,055. Cotton became the principal source of revenue for Egypt at that time.

And when sucess came, it was neither stinted nor uncertain, but burst, as it were, into full bloom at once." (note 3)

Egyptian and American varieties were crossed and crossed again.  In 1825 Sea Island cotton was taken to Egypt and crossed with Jumel creating a new ELS variety known as Ashmouni. Egyptian cottons continued to be improved until 1908 when Ashmouni and Sea Island were crossed to form another variety, Mitafifi. In the early 1900’s Mitafifi was introduced into the Southwestern United States where the USDA was cultivating more varieties of extra long staple cotton. Among the new varieties was the one best known today, Pima, named for the Pima Indians who helped to raise this variety on the USDA experimental farms in Arizona.

• Pima is the generic name for ELS Cotton and there are numerous varieties. It is grown primarily in the U.S., Australia, and Peru.  To be classed as Pima cotton the stable length must be at least 1 3/8 inches.
• Supima is a registered trade name for Pima cotton that is grown exclusively in the United States. In order to use the Supima label mills, manufacturers, and retailers must enter into a licensing agreement with the Supima Association of America. (note 4)
• Egyptian Cotton is any cotton grown in Egypt no matter the staple length.    Much of the ELS cotton grown in Egypt is used for domestic purposes; less than half Egypt’s exported cotton is of an ELS variety. (note 4)

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