Printing inks are a material that is transferred to a printing substrate with the help of a printing form to display image information on surfaces. Printing inks are made up of: colorants (especially pigments), binding agents (essentially resins with fixative characteristics), additives (auxiliary agents to define the consistency, drying or surface hardness) and solvents. The exact composition differs depending on the printing process:
In offset printing the ink is transferred indirectly which means that different ink formulas are required from those used in a direct printing process. These inks contain solvents based on mineral oil and have a relatively high viscosity, whereas highly liquid with rapidly evaporating solvents are used in gravure and flexo printing. Silkscreen printing inks lie between inks used for gravure and offset printing in terms of viscosity depending on the intended application.