Dyes can be classified in several ways, each class has a very unique chemistry, structure and particular way of bonding. Some dyes can react chemically with the substrates forming strong bonds in the process, and others can be held by physical forces. Some of the prominent ways of classification are given below
Natural / Synthetic
Organic / Inorganic
By area and method of application
Chemical classification - Based on the nature of their respective chromophores.
By nature of the Electronic Excitation (i.e., energy transfer colorants, absorption colorants and fluorescent colorants).
According to the dyeing methods
Anionic (for Protein fibre)
Disperse (Polyamide fibres)
US International Trade Commission has advocated the most popular classification of dyes. This system classifies dyes into 12 types, which are given below: