During Manfred Mohr’s solo exhibition at the Musée d’Art Moderne de la Ville de Paris in 1971, “a large white panel was mounted in the exhibition hall at the Museum, a sort of guest book, where visitors could write whatever they wished to say. The panel consisted of sprocketed computer paper (77.5 centimeters by 281 centimeters) placed on a wooden board.” This is what they got. Check out this page to read into details.
I discovered this story today thanks to Wolf Lieser‘s beautiful presentation at Retune Festival in Berlin. After the 1971 exhibition, the panel was shown only once, 40 years later, at Bitforms Gallery.