For hundreds of years, paper and printing techniques are the foundation for distribution of information. Thereby, physical documents enjoy high confidence. To have something in „black and white“ carries significance. But forgery or alteration of documents are nearly as old as the history of writing. Hence the question for the originator is important. Nowadays, because of continual technological development, even individuals can print high-quality documents and duplicates. This can be done with cheap and customary devices. In addition image processing software, like gimp or photoshop, allows to manipulate documents and images easily. Therefore printed documents are often an issue in crimes, e.g. faked proof of identity, copyright theft, or as exhibit in a criminal case. In all this cases it could be useful for law enforcement agencies to, e.g., identify the device or model which was used to print the questionable document.