Signatures on works of art are characterized by their many-sidedness. They consist of letters and simultaneously have graphic qualities as well. The essays in the book take a look at signing practices from the Middle Ages and the modern era based on the example et al. of Albrecht Dürer, El Greco, and Rembrandt. They address aspects of authorship and artistic identity, the intermedial interplay between text and picture, and the intellectual horizons of artists in various cultural milieus in Europe. The technical execution of signatures is thus also examined, as well as the use of different fonts. New perspectives on signatures of artworks are thus developed based on the connection between art-historical, philological, and restoration questions.