Dyestuff, also known as dye, is a colored substance that has an affinity to the substrate to which it is being applied. Both dyestuff and pigments are colored because they absorb some wavelengths of light more than others. Both dyes and pigments are called colorants. The major difference between dyes and pigments is the solubility. Dyestuff, in which the coloring matter is dissolved in liquid, are absorbed into the material to which they are applied. While pigments, consist of extremely fine particles of ground coloring matter suspended in liquid which forms a paint film that actually bonds to the surface it is applied to.