can be implemented in substrates, inks and in the printing itself. They can be made visible to the bare eye or simple equipment such as UV lamps and magnifying glasses. Paper based documents as well as plastic based documents have a lot of security features in common. But some security features are only possible for one or the other. As there are many different products with particular demands, the variety of security features is vast. As means of explanation this picture illustrates a brief introduction into the classification of security features.