March 17, 2010 > TechKnow Talk: Blue Jeans: The Universal Uniform
TechKnow Talk: Blue Jeans: The Universal Uniform
The popularity of blue jeans cuts across geographical and political boundaries, age groups, and economic classes. It is a worldwide phenomenon. Jeans are worn by men, women, and children from all walks of life, in every corner of the globe.
But modern jeans are uniquely American and associated around the world with cowboys of the American west. Jeans are not only fashionable, they are practical, offering an unbeatable combination of comfort and durability.
Not all manufacturers release jeans-specific sales figures, so it is impossible to know how many are sold, but a fair estimate is at least three-quarters of a million pairs of jeans a day in the U.S., and possibly well over a million. Ranging in price from less than $30 to more than $300 each, blue jeans are at least a $15 billion annual industry in the U.S. alone.
Traditional jeans are 100% cotton. There are a variety of manufacturing methods, but all rely on a twill weave. This involves weaving the crosswise (weft) yarn through doubled strands of lengthwise (warp) yarn. The yarn is also tightly twisted to provide strength and durability. This type of cotton twill fabric is called denim. Of course, denim and denim-synthetic fabrics are used not only for jeans, but for all sorts of clothing, including shirts, shorts, skirts, jackets, and hats.
Traditional shuttle looms, in which the weft yarn is passed through the warp with push sticks called shuttles, have given way to modern projectile looms, in which a small capsule trailing the weft fibers is shot through the warp at high speed. These looms have helped denim manufacturers keep pace with dramatically rising demand in recent decades.
The traditional blue jean color is achieved by treating the fabric with indigo dye. This dark blue dye was derived originally from a tropical plant but today most indigo dye is synthetic. Some manufacturers dye only the warp fibers, prior to weaving, giving the fabric a banded look. Others dye the finished fabric as a whole.
Because denim is very tightly woven, the dye may not penetrate completely into the fibers. This in part accounts for the uneven "whitening" of jeans as they age; the outer surfaces are worn away to expose more lightly dyed or un-dyed material. Of course, not all jeans are blue anymore. A variety of dyes are used to create the broad range of colors currently available.
Although U.S. companies dominate the world market, most jeans are actually made overseas, in India, China, and elsewhere, to control the cost of this labor-intensive and high-volume process.
Though denim is a highly durable material, jeans possess the additional advantage of becoming more comfortable with use. This comes from softening of the fabric over time and shaping of the jeans to the wearer's body for an increasingly individualized fit.
To shortcut this process, traditionally achieved by weeks or months of wearing and laundering, manufacturers now offer "pre-wash" treatments. These may be marketed with terms such as pre-washed, stone-washed, or acid-washed. Most such processes involve tumbling the jeans with stones in a chemical bath. The intent is to "break in" or soften the jeans for comfort and to provide a worn or "distressed" appearance.
In addition to giving a new pair of jeans that "lived in" look, pre-washing reduces subsequent shrinkage. Unfortunately, such rough treatment also shortens the life of the jeans.
Though many are still 100% cotton denim, modern synthetic fibers have made their way into jeans as well. Polyester or nylon may be added for strength and shrink resistance. A small percentage of spandex, a highly-elastic, polyurethane-based synthetic fiber, is also used in some jeans to add a bit of stretch to the fabric.
Denim, or more precisely a similar material called serge, was originally produced in the city of Nimes, France. Serge de Nimes was shortened to "denim" sometime in the 18th century.
Similarly, the origin of the term "blue jeans" may be the city of Genoa in northern Italy, which claims credit for first producing blue jeans in the 16th century. Genoa even holds an annual festival to celebrate this historical distinction. The blue fabric used at the time was called in Italian Bleu de Genes (Genoa blue).
But the precursors of trousers we would recognize as blue jeans today are credited to Levi Strauss. A German-born U.S. immigrant, Strauss founded the company bearing his name in 1853 in San Francisco where he sold cloth and other dry goods, mostly to miners. Strauss collaborated with one of his customers, Jacob Davis, to apply for a patent on a copper riveting technique for pockets. The patent was awarded in 1873.
During Strauss's life, the rivets, which greatly strengthened the stress points of a garment, were used mostly for overalls. But over time, jeans became more popular. They were common among cowboys as early as the 1920s and 1930s, and were worn by factory workers in the 1940s.
But it was during the 1950s and 1960s that their popularity exploded, first due to James Dean and motorcycle gang movies, then to the hippie movement. The eager adoption of jeans by these subcultures led to a much broader acceptance into mainstream society by the 1970s.
Of course many other manufacturers now use the copper rivets patented by Strauss. Though its market share has diminished considerably over the last 20 years, Levi's remains the iconic, if not the largest, brand of jeans. Strauss left four nephews when he died in 1902. Today, the company is privately held by descendants and relatives of those men.
Levi Strauss would surely be astonished by the sheer variety and profusion of jeans available today. In addition to many colors, there are styles and fits available for nearly any body type or fashion sense. Several pairs of jeans are likely to be found in the closet of nearly everyone, whether student, teacher, factory worker, or CEO. Few items of apparel have achieved such market penetration.