A dye is a coloured substance that has an affinity, a bond with a physical surface, to the substrate to which it is being applied. Dyes are usually soluble in water. Dyes are used to change the perceived colour of an object. Dyes consist of 2 main parts: chromohore and auxochrome. Before 1856, all dyes were obtained from natural resources. The first synthetic dye, Mauveine, was accidentally discovered by William Henry Perkin in 1856 while he was looking for a cure for malaria. Different dyes are made of different dye molecules. Dyes have colour because they absorb light in the visible spectrum (400–700 nm), have at least one chromophore, have a conjugated system (a structure with alternating double and single bonds), and exhibit resonance …show more content…
The Romans used Indigo as a pigment for painting, medical and cosmetic purposes. Indigo was considered a luxury item due to the natural process of extracting it, therefore making it expensive. Indigo was an important aspect of many of West African traditions. Clothes dyed with Indigo usually signified wealth and were only available to people from wealthy families. In Japan, during the Edo period when it was forbidden to use silk, the Japanese began to import and plant cotton; indigo was the only dye that was able to be used for cotton fiber. In the modern world much of the need for indigo is being met with other types of blue dyes. Most of the indigo produced is synthetic indigo. The main use for indigo dye is for cotton yarn to produce blue jeans. Small amounts of indigo dye are used for dyeing wool and silk. Indigo also has been used as a treatment for a range of ills including scorpion bites and ovarian and stomach cancer. Indigo dye is a very popular dye and is one of the oldest dyes dating back thousands of years. Indigo dye continues to be used widely even though other new blue dyes have been introduced. Indigo dye continues to be the primary colour of blue jeans in the modern world. The dye brings an eye catching blue colour to the material it is applied