The Plus and Minus visual game is made up of 72 cards with various images. Many of these 48 images are on a transparent background, so they can be superimposed to assemble more complex images, thus stimulating childrenâ€™s creative skills. Superimpose several tree cards together and make up a wood. Add the rain or sun or moon or flying birds or passing dog cards and modify the resulting picture at pleasure. Plus and Minus was created in 1970, preceded two years earlier by Munariâ€™s experimental see-through book The Circus in the Mist. This time, Munari produced not a book but a game, made of many images on transparent backgrounds to superimpose and assemble at pleasure by adding or subtracting cards. Bruno Munari (1907-1998) was definitely the most eclectic Italian artist-designer.