Decorating and printing plastic surfaces

In principle, there's no need for surface treatments for plastics, which generally behave well with regard to humidity and corrosion. What's more, as the polymer can be dyed in its mass, painting can be avoided.

However, for reasons of appearance, decoration or printing, and generally to enhance the value of synthetic materials, specific marking or decorating processes are used. This is particularly the case for advertising packaging, assemblies of plastics with other materials (to obtain a tonal identity), to avoid parasitic reflections or provide better durability, etc., and, of course, to display indicative markings.

Here are the main techniques used in plastics marking, depending on the desired effect and the type of rigid or flexible substrate: preparatory treatments, printing on small or large surfaces, metallic deposits and printing on films or flexible sheets, with a clear distinction between localized printing providing information in the form of colored or uncolored characters (such as a brand name, logo or instructions) and decoration covering an entire surface (which may provide only an appearance or also a protective function).