The defining ingredient in inks is pigment. These particulate solids selectively absorb or reflect light to produce a color. But as insoluble materials, pigments do not automatically lend their tinge to other objects.

These colors are made transferrable by mixing pigments with a vehicle substance. Unlike dyes, pigment crystals do not alter their shape or characteristics when blended. But the vehicle’s composition affects the ink product’s properties – luminosity, viscosity, abrasiveness, and tackiness.