printing ink

printing ink (In French encre d’impression) pasty-viscous to watery mixture of color agents, film formation agents and possibly also solvents, auxiliary materials and additives. The purpose of printing ink is to achieve light-dark and or colored contrasts on the substrate. Depending on the printing process (printing ink transfer, in offset printing also the wet and waterless wetting principles) and absorbency of the substrate surface (ink absorption capacity) the stable adhesion of the color agents is induced using different principles of ink drying. Other technical requirements concern spectral properties, gloss, covering capacity, light fastness, chemical and mechanical resistance, environment-friendliness (freedom from hazardous substances, migration behavior, deinking/recycling capacity, possibly binders from vegetable oils), also special pigment effects (reflection, fluorescence). Classification by application is also possible: book printing, printing on lightweight paper, illustration/art printing, securities printing, newspaper etc.