Denim jeans, dyed with natural or synthetic indigo, are the most popular garments worn by individuals of all ages and approximately one billion pairs of jeans are produced per annum. Traditionally, denim has been woven with cotton in a warp face twill weave, in which the warp is blue whereas the weft is white. Dyeing is usually performed with pure indigo, or indigo combined with a sulfur dye to...