Color-aid paper is an American product comprising pre-packed sets of brightly hued paper. For the collage each letter was first drawn upside down on the reverse of the paper, cut out and then glued onto the backing cardboard using Cow Gum glue. Each collage in the edition can be considered unique since the colour variations used change each time. During the design phase, Alighiero Boetti advised the use of 'moon' colours for 'Talvolta luna' and 'sun' colours for 'Talvolta sole', also indicating the possibility of turning the work upside down depending on the owner's mood in a particular moment, whether cheerful or melancholic. The edition was realized by the artist's friend and collaborator, the photographer Giorgio Colombo.