The slender Roehr œuvre, encompassing approximately 600 works, includes text and typo-visual montages, floor-, object-, and photomontages, as well as film and audio-montages, all untitled and uniformly numbered. Among the first montages are the typo-montages – perforated punchcards, quadratic fields of single letters, numbers or punctuation marks, typed without any spaces on an ordinary typewriter. At first, Roehr used a mechanical typewriter. However, the machine’s irregular strokes didn’t satisfy his demand. Eventually, the implementation of IBM’s electronic typewriter enabled him to create perfectly even fields of identical characters. From the perspective of historical development of art during the early 1960s, Roehr’s typomontages represent a radicalization of the serial structures of ‘Zero’ art and the texts of Concrete Poetry, as well as offering a counterpart to Carl Andre’s Typewriter Drawings, which were being developed at the same time in New York.