Karel Martens is a Dutch designer and teacher. After training at the school of art in Arnhem, he has worked as a freelance graphic designer, specializing in typography. Alongside this, he has always made free (non-commissioned) graphic and three-dimensional work. His design work ranges widely, from postage stamps, to books, to signs on buildings. All this work is documented and celebrated in the books Drukwerk / printed matter and Karel Martens: counterprint. Martens has taught graphic design since 1977. His first appointment was at the school of art at Arnhem (until 1994). He was then attached to the Jan van Eyck Academie in Maastricht (1994–9). From 1997 he has been a visiting lecturer in the graphic design department at the School of Art, Yale University. In that year, together with Wigger Bierma, he started a pioneering school of postgraduate education within the ArtEZ, Arnhem – the Werkplaats Typografie – where he still teaches.