Pigmented inks contain agents that ensure adhesion of the pigment to the surface and prevent it from being removed by mechanical abrasion. These materials are typically referred to as resins (in solvent-based inks) or binding agents (in water-based inks). Pigmented inks are advantageous when printing on paper because the pigment stays on the surface of the paper. This is desirable because more ink on the surface of the paper means less ink needs to be used to create the same intensity of color.