1. Ink composition and characteristics

Whatever the application, ink components can be divided into three categories.

• Colorant

  Most often, it consists of very finely divided pigments in colloidal suspension in the ink's fluid phase. For some inks (inkjet), soluble colorants are used.

• Vehicle

  This fluid phase, also known as "varnish", is made up of a mixture of polymers (resins), which act as binders, and diluents and/or solvents. The vehicle has multiple functions: to transport the pigments, to bind them to the printing substrate and, finally, to protect them by forming a continuous film. The choice of ink vehicle determines the drying process.

• Additives

  These products, which vary in nature,...