Earlier, textile dyes were made out of natural sources, like herb madder extracted from plants. Modern dyes are now used for coloring both synthetic and natural fibers.
Take a look at some common types of fabric dyes:
Its usage is common for coloring natural fibers like cashmere, wool and silk. It can also color nylon textiles. Some of these are quite toxic, while others are quite mild and safe that it can be used for coloring food also. These dyes are used as acidic solutions, in which the acid part is typically given by harmless citrus or natural vinegar.
These are used for the purpose of coloring synthetic fabrics like polyester. These are not easily dissolved in water, but its molecules disperse easily in the polymer that needs to be colored. It requires temperature of around 266 degree Fahrenheit and high pressure while using it for dying purpose.
These ones are used for coloring cellulose fibers like linen, cotton, or hemp. However some of these dyes are created particularly for silk and wool. It induces bright colors in fabrics, and the color does not wash out or fade away. The molecules of these dyes bond with cellulose molecules forming a single molecule.