Denim is a sturdy cotton warp-face textile in which the weft passes under two or more warp threads. This twill weaving produces a diagonal ribbing that distinguishes it from cotton duck.Denim was traditionally colored blue with indigo dye to make blue jeans, although “jean” formerly denoted a different, lighter, cotton fabric. The contemporary use of the word “jeans” comes from the French word for Genoa, Italy