jeans

Jeans are trousers cut from denim, a sturdy twill-weave cotton fabric dyed with indigo. The twill structure, where warp threads pass over two weft threads in offset rows, creates diagonal ribs that run at roughly 45 degrees across the cloth. This geometry gives denim its characteristic strength and slight stretch. A pair of jeans typically weighs between 600 and 700 grams and costs manufacturers 4 to 8 dollars per unit in fabric and basic labor, though retail prices vary wildly by brand and finishing.

The garment descends from work pants worn by Nîmes textile workers in 18th-century France, where the twill was called serge de Nîmes. American miners and ranch hands adopted denim work trousers in the 1870s, particularly designs reinforced at stress points with copper rivets at pocket corners. This rivet detail, patented by Levi Strauss and Jacob Davis in 1873, became the defining mark of jeans construction and persists in almost all modern versions.

Manufacturing jeans involves cutting individual pattern pieces from laid-up denim rolls, then sewing them with chain-stitch or lock-stitch seams, often with reinforced bartacking at crotch and seam intersections. Dye vats run at temperatures around 60 to 80 degrees Celsius for indigo dyeing, which is a vat process requiring reduction chemistry and careful oxidation after dyeing to set color. Shrinkage during finishing typically ranges from 3 to 8 percent, depending on whether the cloth has been pre-shrunk or left raw.

Variants and finishing

Denim weight is measured in ounces per square yard, typically ranging from 10 to 16 ounces for apparel-grade cloth. Heavier denims wear longer but are stiffer and take longer to break in. Modern finishing includes stone washing (pumice tumbling), enzyme treatments, and chemical fading to create worn appearances on new garments. Stretch versions incorporate 2 to 4 percent elastane to improve comfort and fit retention. Sanforizing, a heat-pressure process, can reduce shrinkage to under 2 percent.

Quality issues in jeans manufacture center on seam slippage (threads pulling apart rather than breaking), abrasion resistance in high-friction areas like the crotch, and color bleeding or uneven fading. Indigo dyes shed significantly in the first five to ten washes; manufacturers often manage this through resin treatments or multiple rinse cycles before packaging. The garment remains the highest-volume single pant type produced globally, with annual output exceeding two billion pairs across all manufacturers.