Synthetic dyes quickly replaced the traditional natural dyes. They cost less, they offered a vast range of new colors, and they imparted better properties to the dyed materials. Dyes are now classified according to how they are used in the dyeing process.
Almost all the colors that you see today are Synthetic dyes. Synthetic dyes are used everywhere in everything from clothes to paper, from food to wood. Synthetic dyes today has evolved into a multi billion dollar industry.
They are widely used for dyeing and printing in a broad range of industries. There are over 10,000 dyes, and the annual production globally, exceeds over 7 × 105 metric tones. Cheaper to produce, brighter, more color-fast, and easy to apply to fabric, these synthetic dyes changed the playing field.
Scientists raced to formulate gorgeous new colors and before long, dyed fabric was available to all, and natural dyes had become obsolete for most applications.
The synthetic dyes, can be named according to the chemical structure of their particular chromophoric group. For example, diphenylmethane derivatives, triphenylmethane compounds oxazine compounds, xanthene compounds, Azo dyes are one of the most popular varieties of synthetic dyes.
Today it is being used up to 90% in the dyeing units, as they are versatile and simple to synthesize. Most of the synthetic dyes with a few exception are aromatic organic compounds which can be divided into groups like non-ionic (oil soluble), cationic, and anionic. A typical example of Cationic dye is Methyl violet, while Azo dyes are anionic dyes.