The word "denim" comes from the French word "serge de Nimes", as it is a heavy duty fabric which originated in Nimes, France. It is traditionally woven with 100 percent cotton yarn, but in order to control shrinking and wrinkles, it is commonly blended with polyester or spandex, according to Ohio State University Extension.
Carding and Spinning
The initial process of constructing denim fabric is carding. Carding is the process of removing foreign matter from the cotton fibers. In doing so, the fibers are pulled into a web-like form. The fibrous web is made into a rope-like strand called a "sliver," according to the online resource Textile Exchange. The sliver is then spun into yarn through the use of a spinning machine.
Denim fabric is synonymous with the color blue. Indigo, a plant-based dye, has been used for dyeing fabric since the ancient times. It is known for its durability as well as its dark color tone, making stains less noticeable. In recent years, synthetic dyes have been produced.
Denim fabric is a twill weave comprising blue and white yarns. The blue, or indigo, yarn in denim fabric is known as "warp thread". Warp threads run lengthwise, parallel to the selvage. The white yarns is known as filler thread or "weft thread". Weft threads run the width of the fabric.
A twill weave is defined as a fabric that is constructed by warp and filler yarns, creating a diagonal on the right side, or surface, of the fabric The job of the weaving machine is to interlace the warp yarn with the filler yarn. Denim is considered to be a "right-hand twill", which means that the dominant color (usually blue) is seen on the fabric's surface, according to Denver Fabrics.
When the weaving machine has completed the fabric, it is then inspected for possible weaving defects. The fabric goes through processes known as brushing and singeing, which eliminates any impurities as well as even out the surface of the material. The fabric is also washed to give it a faded look. There are a variety of washes which greatly alter the look of the denim fabric.