Colorants can be divided into dyes and pigments, the main difference is solubility.

Dyestuff are soluble in water, oil, organic solvents, etc. They generally contain color-emitting and color-assisting groups within the molecule, and have strong dyeing ability, bright color and complete chromatography. It is mainly used for textile fiber printing and dyeing

Pigments are insoluble in water and solvents, and are the main colorants used in plastics and rubber. They are dispersed into fine particles in plastics and rubber and colored by masking action.