For users of printing or copying equipment, as well as manufacturers of toners, inks, and digital printing presses, the question often arises as to whether the printed document will remain legible for several decades. In some cases, also the issue of the forgery security of the document is relevant. Even when signing documents, it must be ensured that the signature made with a writing instrument remains undoubtedly recognizable. What options are there to verify the desired "permanence and durability" of the document in advance?